>> within hours, 100 marines rushed to mule hill and the mexican army retreats. a year later, the u.s. wins the mexican-american war and triples in size stretching from the atlantic to the pacific. largely due to polk's political ten nasty and kit carson's efforts on the ground, manifest destiny is fully realized. after riding over land to st. louis, carson catches the train for washington to deliver fremont's field reports to the president. ♪ >> washington, d.c., at the time of kit carson's arrival was becoming much more sophisticated and just imagine, this man had