One group heading west was the Mormons, and their reasoning was not as innocent and ambitious. Mormons sought to avoid religious discrimination. Joseph Smith had initially led them west, but after his assassination, Brigham Young took over and led the Mormons to Mexico. This expansion led Americans to enter territories belonging to other nations – for example the American colony in Mexico. This caused conflict in Texas when they decided to rule themselves. Another example is the “fight” for Oregon after Polk was elected president. However, this was by no means a battle. In reality, this was just a bluff by Polk, when his real plan was to make a deal with England over the territory. Now, all this expansion may have caused conflicts and battles with other countries, but these battles were insignificant compared to the inevitable war caused by the expansion - the civil war.