Final answer:
The Pacific Railroad Act helped the United States expand westward by supporting the construction of a transcontinental railroad through federal land grants and loans.
Step-by-step explanation:
The Pacific Railroad Act was passed by the U.S. Congress in 1862 with the goal of expanding the United States westward by promoting the construction of a transcontinental railroad. This act provided federal support, in the form of land grants and loans, to private companies that would undertake the massive task of building the railroad. It allowed for the construction of the First Transcontinental Railroad, which connected the existing rail networks in the east with the rapidly growing settlements in the west.
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