Final answer:
The Pacific Railroad Act of 1862 was a legislative measure that facilitated the establishment of the transcontinental railroad, supporting westward expansion and the free soil movement by providing land and aid to railroad companies. so, option a is the correct answer.
Step-by-step explanation:
The "Pacific Railroad Act" of 1862 was legislation passed by the U.S. Congress to aid in the construction of a transcontinental railroad. This was one of the federal government assistance measures designed to promote the westward expansion of the United States, encouraging settlement and economic development. The act provided for the construction of a rail line west from Omaha, Nebraska by the Union Pacific Railroad, and east from Sacramento, California by the Central Pacific Railroad. Thanks to the act, these companies received ownership of public lands around their tracks and land grants to help with the building of the railway.
Another crucial motivation behind the Pacific Railway Act, along with the Homestead Act, arose from President Abraham Lincoln's concern during the Civil War about the westward expansion of slavery. With the aim of expanding the "free soil" mentality, the act supported the establishment of railroads to facilitate the movement of free-labor farmers, goods and resources, thereby strengthening the Union's infrastructure and economy.
Moreover, the transcontinental railroad's completion eventually became critical in transforming the American West, despite some later conflict with groups such as farmers, who had grievances against railroad businesses as evident in the actions they took, which led to the Interstate Commerce Act.