Grain and what other product were shipped to the manufacturing centers of the East by railroad

The answer is cattle. I checked in my history book and it said they mainly shipped wheat and cattle on that train.

Federal Government contracted millions of acres of land for the development of transportation. The land was used for construction of major transcontinental railroads which paved way for the easy and quick transportation of goods from America to the eastern countries.

Central Pacific Railroad is the first cross continental railroad which connected two continents for enhancing trade relationships. Slow horse carriages were relied upon before the emergence of railroads. It was time consuming.

Today freight train carries commercial goods to the continents without and delay or damage to the goods. Both grain and steers where transported to the eastern butchers from the west.