What did the U.S. government promise to the railroads for laying track all across the country?

The U.S. government promised substantial land grants and financial incentives to railroad companies for laying track across the country. These included large parcels of land adjacent to the rail lines, which the companies could sell or use to fund construction. Additionally, the government provided loans and subsidies to help finance the construction of the railroads, aiming to promote westward expansion and economic development.