Railroads, as you know, are large, connected series of tracks and trains. These were very useful in the Westward Expansion, since they meant easy transportation of bulk goods and riches across a 2,030-mile system from Omaha to Sacramento. When gold was discovered in California, everyone raced over to claim the land. The U.S. won the Mexican War to claim California, but Californians knew they needed railroads to transport things, which meant wealth. The American men knew that railroads were the key to scouting the country for its gold and riches. There was also a great dispute over where the railroads would be placed. Where it would be placed was a great factor in where slave-filled or free states would be distributed. This stalled the building of the railroads for quite some time; about a decade. The technology to build a railroad of this sort was already around by the mid-1840's. They started by building a small line in Sacramento, California's capital, which was a link for the gold sites. The Pacific Railroad Act "authorized the Central Pacific Railroad to build east from Sacramento and the Union Pacific Railroad to build west from Omaha, on the Missouri River". This was signed by President Lincoln in 1862. In 1862, California changed. The trans-continental telegraph was completed and communication was quicker. Now, the East and West met. The country was growing rapidly, but the frontier was soon closed due to the Civil War. In 1900, people settled down with a railroad and the United States as we now know it was formed.