railroad tycoons paid off congress to pass the Pacific Railway Act of 1864 it doubled the size of land grants awarded to railways

As you can see from the above map, the total number of acres granted to the railroads was enormous. In total, the railroads received more than 175 million acres of public land

If the Homestead Act was Exhibit A of congressional and Government Activism, the Pacific Railway Acts were "Activist Government on Steroids".

http://www.blackdiamondnow.net/black-diamond-now/2014/10/the-pacific-railway-act-of-1862.html