This is a writ of error bringing into review a decree of the supreme court of Florida, dismissing a bill in equity filed by the plaintiff in error, which sought to enjoin the defendant, a collector of revenue under the laws of Florida for the county of Escambia, from collecting, by a sale of property levied on for that purpose, certain taxes claimed by him to be due from the complainant The ground of our jurisdiction is, as stated and shown in the record, that in the cause wherein the decree complained of was rendered there was drawn in question the validity of a statute of the state of Florida, to-wit, 'An act entitled an act for the assessment and collection of revenue,' approved March 5, 1881, wherein and whereby certain taxes for state and county purposes were imposed upon the line of railroad extending from the city of Pensacoia, in the state of Florida, to the northern boundary of the state of Florida, in the direction of Montgomery, Alabama, of which railroad the plaintiff in error is in possession and is owner; the validity of this statute being questioned on the ground that it was repugnant to the constitution of the United States, in that it impaired the obligation of a contract, and the decision of the supreme court of Florida being in favor of its validity. The contract, the obligation of which it is alleged has been thus impaired, and of which the plaintiff in error claims the benefit, is asserted to arise as follows: The general assembly of the state of Florida passed an act, which took effect January 6, 1855, entitled 'An act to provide for and encourage a liberal system of internal improvements in this state,' the preamble to which recites that–– 'The constitution of the state declares 'that a liberal system of internal improvements, being essential to the development of the resources of the country, shall be encouraged by the government of this state, and it shall be the duty of the general assembly, as soon as practicable, to ascertain by law proper objects of improvements in relation to roads, canals, and navigable streams. and to provide for a suitable application of such funds as may be appropriated for such improvements." The act then proceeds to create an internal improvement fund to aid in the construction of certain described railroads, and other works of internal improvement, by means of corporations organized or to be chartered for that purpose; and the eighteenth section provides as follows: 'That the capital stock of any railroad company accepting the provisions of this act shall be forever exempt from taxation, and the roads, their fixtures and appurtenances, including workshops, warehouses, vehicles, and property of every description, needed for the purpose of transportation of freight and passengers, or for the repair and maintenance of the roads, shall be exempt from taxation while the roads are under construction, and for the period of thirty-five years from their completion, and that all the officers of the companies, and servants and persons in the actual employment of the companies, be and are hereby exempt from performing ordinary patrol or militia duty, working on public roads, and serving as jurors.' By an act of the general assembly of Florida, approved December 14, 1855, it was enacted–– 'That a line of railroad to be constructed from the city of Pensacola, or any other point or points on the waters of Pensacola bay or the waters of St Andrew's bay, to the north line of the state, leading in the direction of Montgomery, Alabama, shall be considered proper improvements to be aided from the internal improvement fund in the manner provided for, or may hereafter be provided for, in 'An act to provide for and encourage a liberal system of internal improvements in the state,' approved January 6, 1855.' The Alabama & Florida Railroad Company, by an act approved January 8, 1853, had been incorporated to build a railroad falling within that description, to extend from some point on the bay of Pensacola to some point on the boundary line between the states of Florida and Alabama, to meet and connect with a railroad leading thence to the city of Montgomery. This company, it is alleged in the bill, built and for a time operated the line of railroad contemplated by its charter, and became entitled to the benefits and privileges of the internal improvement act of 1855, by accepting its provisions and complying with its conditions. Its line of railroad was completed about January 1, 1860. By virtue of a decree of foreclosure and sale at the suit of trustees of a first mortgage, to satisfy the bonds secured thereby, the railroad of the Alabama & Florida Railroad Company, and all the rights, privileges, and franchises of the said company, were sold and conveyed on August 7, 1872, to one A. E. Maxwell, his heirs and assigns, in trust, and by him were sold and conveyed on December 10, 1872, to the Pensacola & Louisville Railroad Company, a corporation created by the laws of Florida. The original act incorporating the last-named company was passed July 16, 1868, but it appears to have been reorganized by an amendatory act which took effect February 4, 1872, the eighteenth section of which is as follows: 'That the Pensacola & Louisville Railroad Company, having become the assignee of the Alabama & Florida Railroad, of Florida, and the franchises of the said corporation, and being in possession of and operating the said line of road, which corporation was exempt from taxation for a limited period, the said Pensacola & Louisville Railroad Company and its property, now owned or hereafter to be acquired, shall also be exempt from taxation during the remainder of said period.' On May 6, 1878, in pursuance of a decree of the circuit court of the state of Florida, sitting in Leon county, a sale and conveyance was made transferring the title of the Pensacola & Louisville Railroad Company in and to its road and other property, 'together with all the franchises, rights, privileges, easements, and immunities' of that company, to the Pensacola Railroad Company. This company was a corporation of the state of Florida, created by an act of the general assembly which took effect February 27, 1877. The second section of that act is as follows: 'Sec. 2. Be it further enacted, that the said Pensacola Railroad Company be, and it is hereby, authorized and empowered to acquire by purchase and assignment all the property, rights, franchises, privileges, and immunities of the Pensacola & Louisville Railroad Company, a corporation created by an act of the general assembly of the state, approved July 16, A. D. 1868, whether the same were acquired under the laws of the states of Florida or Alabama, or the laws of the United States, or as the assignee and successor of the Alabama & Florida Railroad Company; and upon completion of the said purchase and assignment, the said Pensacola Railroad Company shall be deemed in law and equity to be fully invested with and entitled to all the said property, rights, franchises, privileges, and immunities of said Pensacola & Louisville Railroad Company, as though the same were originally granted to or acquired by the said Pensacola Railroad Company.' By the thirteenth section of the act of 1872, amending the charter of the Pensacola & Louisville Railroad Company, it was provided that 'it shall be lawful for said company to purchase, lease, acquire an interest in, to unite or consolidate with, lease or sell to, any other railroad company in or out of the state, and to make the same one company, with a consolidated stock and property, and with one board of directors,' etc. The right under this section to sell and transfer its property and franchises to a corporation of another state, it is claimed, passed from the Pensacola & Louisville Railroad Company to the Pensacola Railroad Company; and accordingly, on October 20, 1880, the Pensacola Railroad Company conveyed to the Louisville & Nashville Railroad Company, the plaintiff in error, its railroad from its junction with the Mobile & Montgomery Railway, to its terminus in Pensacola bay, its property, real and personal with certain exceptions, all its franchises, except the franchise to be and exist as a corporation, rights, privileges, easements, and immunities, by virtue of which conveyance the plaintiff in error claims in the bill that it became entitled to all the rights, property, privileges, franchises, and immunities of the Alabama & Florida Railroad Company, the Pensacola & Louisville Railroad Company, and the Pensacola Railroad Company, under the various acts incorporating these companies, and acts amendatory of the same. The plaintiff in error, the Louisville & Nashville Railroad Company, is a corporation of Kentucky, and by an amendment to its charter, which took effect March 6, 1878, reciting that its stockholders had become largely interested in the commerce and railroad business between the states of Kentucky and Tennessee and the southeast, and the several railroad connections in that part of the country, by an extension of its system, was enabled 'to operate, lease, or purchase, upon such terms or in such manner as they deem best, any railroad in any other state or states deemed necessary for the protection of the interest of the stockholders.'