
233 U.S. 211 (1914)
UNION LIME COMPANY
v.
CHICAGO AND NORTHWESTERN RAILWAY COMPANY.
No. 529.
Supreme Court of United States.
Argued March 2, 1914.
Decided April 6, 1914.
ERROR TO THE SUPREME COURT OF THE STATE OF WISCONSIN.
Mr. George Lines, with whom Mr. Willet M. Spooner, Mr. Fred C. Ellis and Mr. Louis Quarles were on the brief, for plaintiff in error.
Mr. Edward M. Smart, with whom Mr. Edward M. Hyzer was on the brief, for defendant in error, Chicago & Northwestern Railway Company.
Mr. Walter Drew, with whom Mr. L.E. Lurvey was on the brief, for defendant in error, Eden Independent Lime and Stone Company.
By leave of the court, Mr. W.C. Owen, Attorney General of the State of Wisconsin, and Mr. Walter Drew, filed a brief as amici curiae.
*216 MR. JUSTICE HUGHES delivered the opinion of the court.
This proceeding was instituted by the Chicago and Northwestern Railway Company to take land for a spur, the construction of which had been ordered by the Railroad Commission of the State. The land was owned by the Union Lime Company, the plaintiff in error, and the application was resisted upon the ground that it was sought to be taken for a private, and not a public, use and therefore that its taking would operate as a deprivation of the property of the plaintiff in error without due process of law and a denial to it of the equal protection of the laws contrary to the Fourteenth Amendment. This contention was overruled by the Supreme Court of the State which affirmed the judgment in condemnation (152 Wisconsin, 633), and this writ of error was sued out.
The proposed track was to form an extension of an *217 existing spur, owned and operated by the Railway Company, which leads from its main line to the quarries and kilns of two lime companies; one of these companies is the plaintiff in error at whose works the spur now terminates. Beyond these works lie those of the Eden Independent Lime and Stone Company which applied to the Railroad Commission for an order requiring the Railway Company to extend the spur to its plant. It is provided by § 1797-11m of the Wisconsin Statutes that every railroad shall acquire the necessary right-of-way and shall construct and operate a "reasonably adequate and suitable spur track" whenever it does not necessarily exceed three miles in length, is "practically indispensable to the successful operation" of any existing or proposed manufacturing establishment, and is not "unusually unsafe" or "unreasonably harmful." The railroad may require the person, firm, or corporation primarily to be served thereby to pay the legitimate cost of acquiring, by condemnation or purchase, the necessary right-of-way for the spur and of its construction, as determined by the Railroad Commission. By § 1797-12n, the Commission is authorized to receive complaints, in case of the failure or refusal of railroads to perform the prescribed duty, and to make appropriate orders.[1] Acting under these sections, the *218 Commission directed the Railway Company to extend the spur as desired by the Eden Company and thereupon this proceeding was brought to condemn the land for the right-of-way.
The assignments of error come to the single point,  as to the character of the use. The State through its highest court declares the use to be a public one, and we should accept its judgment unless it is clearly without ground. *219 Fallbrook Irrigation District v. Bradley, 164 U.S. 112, 160; Clark v. Nash, 198 U.S. 361, 369; Strickley v. Highland Boy Mining Co., 200 U.S. 527, 531; Offield v. N.Y., N.H. & H.R.R. Co., 203 U.S. 372, 377; Hairston v. Danville & Western Rwy. Co., 208 U.S. 598, 607. The general authority to exercise the power of eminent domain for the construction of spurs is found in § 1831-a, Stats. (Wis.), which provides: "Every railway company . . . may build, maintain and operate branches and spur tracks from its road or any branch thereof to and upon the grounds of any mill, elevator, storehouse, warehouse, dock, wharf, pier, manufacturing establishment, lumber yard, coal dock or other industry or enterprise, . . .; and every such company may acquire by purchase or condemnation in the manner provided in this chapter for the acquisition of real estate for railway purposes, other than for its main track, all necessary roadways and rights *220 of way for such branches, spur tracks," etc. The Supreme Court of the State sustained the validity of this provision in Chicago & Northwestern Rwy. v. Morehouse, 112 Wisconsin, 1, holding (p. 11) that "the fact that a spur track may run to a single industry does not militate against the devotion of the property thereto being a public use thereof, so long as the purpose of maintaining the track is to serve all persons who may desire it, and all can demand, as a right, to be served, without discrimination."
In Union Lime Company v. Railroad Commission, 144 Wisconsin, 523, the court had under review an earlier order of the Commission requiring the railroad to build the spur extension now in question and, while that order was set aside because a proper hearing had not been afforded, it was held that the spur would not be a private track, but would be devoted to a public use. In the view that the tracks contemplated would be of this character, the court sustained the statutes (§§ 1797-11m and 1797-12n), under which the Commission was proceeding, against the same objections that are now raised. The court said (id. pp. 533-534): "Such track when built becomes a portion of the trackage of the railroad. The fact that its initial cost is borne by the party primarily to be served, with provisions for subsequent equitable division of such cost, does not make it a private track nor change the nature of its use. Over it the products of the industry find their way into the markets of the world, and every consumer is directly interested in the lessened cost of such products resulting from the building and operation thereof. That these products are supplied by a single owner, or by a limited number of owners, affects the extent and not the nature of its use  the track is none the less a part of the avenue through which the commodities reach the public. Subject to the equitable division of initial cost, the track is at the service of the public as much as any other, and it constitutes an integral part of the railroad system. The *221 duty to maintain and operate it rests upon the railroad. Except that it is relieved of the initial cost of right of way and construction, the track stands in the same relation to it that any other portion of its track does. The owner of the industry obtains no interest in or control over it beyond that of being served by it equally with any one else who may desire to use it." This decision was followed in the present case. 152 Wisconsin, 633, 637.
Assailing this ruling, the plaintiff in error insists that the statute itself (referring to §§ 1797-11m and 1797-12n) authorizes the taking of property for private use, and that, being unconstitutional on its face, it cannot form the basis of any valid proceeding. It is said, in the first place, that the statute does not declare in terms or by necessary implication that the use for which the property is to be taken is a public use. But this contention is plainly without merit as the statute must be read in the light of the construction placed upon it by the state court which has held the described use to be a public one. The judgment of the State so far as it is competent to determine the matter has thus been fully expressed.
It is urged, further, that the statute is necessarily invalid because it establishes as the criterion of the Commission's action the exigency of a private business. This objection, however, fails to take account of the distinction between the requirements of industry and trade which may warrant the building of a branch track and the nature of the use to which it is devoted when built. A spur may, at the outset, lead only to a single industry or establishment; it may be constructed to furnish an outlet for the products of a particular plant; its cost may be defrayed by those in special need of its service at the time. But none the less, by virtue of the conditions under which it is provided, the spur may constitute at all times a part of the transportation facilities of the carrier which are operated under the obligations of public service and are *222 subject to the regulation of public authority. As was said by this court in Hairston v. Danville & Western Rwy. Co., supra (p. 608): "The uses for which the track was desired are not the less public because the motive which dictated its location over this particular land was to reach a private industry, or because the proprietors of that industry contributed in any way to the cost." There is a clear distinction between spurs which are owned and operated by a common carrier as a part of its system and under its public obligation and merely private sidings. See De Camp v. Hibernia R.R. Co., 47 N.J. Law, 43; Chicago &c. R.R. Co. v. Porter, 43 Minnesota, 527; Ulmer v. Lime Rock R.R. Co., 98 Maine, 579; Railway Company v. Petty, 57 Arkansas, 359; Dietrich v. Murdock, 42 Missouri, 279; Bedford Quarries Co. v. Chicago &c. R.R. Co., 175 Indiana, 303.
While common carriers may not be compelled to make unreasonable outlays (Missouri Pacific Rwy. Co. v. Nebraska, 217 U.S. 196), it is competent for the State, acting within the sphere of its jurisdiction, to provide for an extension of their transportation facilities, under reasonable conditions, so as to meet the demands of trade; and it may impress upon these extensions of the carriers' lines, thus furnished under the direction or authority of the State, a public character regardless of the number served at the beginning. The branch or spur comes into existence as a public utility and as such is always available as localities change and communities grow. The Supreme Court of Wisconsin has left no doubt with respect to the public obligations imposed upon the carrier in relation to the spurs and branches to be provided under the statute in question, and we find no ground for the conclusion that this enactment was beyond the state power.
It is also contended by the plaintiff in error that the finding by the state court that the use in the present case is a public one is not supported by the facts. But this *223 criticism of the court's finding is in substance a repetition of the argument that is urged against the validity of the statute and what has been said upon that point is applicable.
The judgment is affirmed.
Affirmed.
NOTES
[1]   These sections, enacted by Chapter 352 of the Laws of 1907, as amended by Chapter 481 of the Laws of 1909 and Chapters 193 and 663, § 342 of the Laws of 1911, are as follows:

"Section 1797-11m. 1. Every railroad shall acquire the necessary rights of way for, and shall construct, connect, maintain, and operate a reasonably adequate and suitable spur track, whenever such spur track does not necessarily exceed three miles in length, is practically indispensable to the successful operation of any existing or proposed mill, elevator, storehouse, warehouse, dock, wharf, pier, manufacturing establishment, lumber yard, coal dock, or other industry or enterprise, and its construction and operation is not unusually unsafe and dangerous, and is not unreasonably harmful to public interest.
"2. Such railroad may require the person or persons, firm, corporation or association primarily to be served thereby, to pay the legitimate cost and expense of acquiring, by condemnation or purchase, the necessary rights of way for such spur track, and of constructing the same, as shall be determined in separate items by the commission, in which case the total estimated cost thereof shall be deposited with the railroad before the railroad shall be required to incur any expense whatever therefor; provided, however, that when any such person, firm, corporation or association, shall be required by the commission to deposit with the railroad, the total estimated cost, as herein provided, such person, firm, corporation or association, may offer or cause to be offered, a proposition in writing to such railroad, to construct such spur track, such proposition to be accompanied by a surety company bond, running to such railroad, and conditioned upon the construction of such spur track in a good and workmanlike manner, according to the plans and specifications provided by such railroad, and approved by the commission, and deposit with such railroad the estimated cost of the necessary right of way for such spur track; and whenever such proposition and security company bond shall be offered the person, firm, corporation, or association primarily to be served thereby, shall not be required to deposit as herein provided, as the total estimated cost of such construction, an amount in excess of the estimated cost of the right of way, and the total amount stated in such written proposition. Provided further that before the railroad shall be required to incur any expense whatever in the construction of said spur track, the person, firm, corporation, or association primarily to be served thereby, shall give the railroad a bond to be approved by the commission as to form, amount and surety, securing the railroad against loss on account of any expenses incurred beyond the amount so deposited with the railroad.
"3. Whenever such spur track is so connected with the main line, as herein provided, at the expense of the owner of such proposed or existing mill, elevator, storehouse, warehouse, dock, wharf, pier, manufacturing establishment, lumber yard, coal dock, or other industry or enterprise, and any person, firm, corporation, or association shall desire a connection with such spur track, application therefor shall be made to the commission, and such person, firm, corporation, or association shall be required to pay to the person, firm, corporation, or association that shall have paid or contributed to the primary cost and expense of acquiring the right of way for such original spur track, and of constructing the same, an equitable proportion thereof, to be determined by the commission, upon such application and notice, to the persons, firms, corporations, or associations that have paid or contributed toward the original cost and expense of acquiring the right of way and constructing the same.
"Section 1797-12n. In case of the failure or refusal of any railroad to comply with any of the provisions of sections 1797-11m and 1797-12n, the person or persons, firm, corporation or association aggrieved thereby may file a complaint with the railroad commission setting forth the facts, and the said commission shall investigate and determine the matter in controversy, in accordance with the provisions of sections 1797-1 to 1797-38, inclusive, and any order it shall make in said proceeding shall have the same force and effect as an order in any other proceeding properly begun under and by virtue of the provisions of said sections."
