westward on his own while Frémont continued on to California. At the time, the Oregon Country was under joint administration by the United States and the United Kingdom, but in practical terms it was controlled by the Hudson's Bay Company at Fort Vancouver. Gilpin settled among the growing community of U.S. settlers in the Willamette Valley and became active in the organization of a provisional government. At the landmark convention at Champoeg, he helped draft a petition requesting support for the provisional government from the United States Congress. Gilpin himself was charged with carrying the Willamette petition back east. On his way back through Missouri, he helped publicize the Pacific Northwest and stir up "Oregon fever". He delivered the petition to Congress in 1845, then wrote memoirs of his travels in the Pacific Northwest to emphasize its potential for trade and settlement. The Central Gold Region In 1846, during the Mexican–American War, he was commissioned as Major of the 1st Missouri Mounted Infantry Regiment and marched to Chihuahua City in the successful bloodless campaign to capture New Mexico. He was considered to have served with distinction in the campaign and was later given command of a mounted infantry battalion to protect the Santa Fe Trail against attacks by Native Americans. Gilpin was also involved with the ill-fated Fort Mann, just west of what is now Dodge City, Kansas. The man Gilpin put in charge of the post created havoc and Gilpin attempted to rectify some of the problems caused there. After the end of the war in 1848, he returned to Missouri and resumed his law practice. He made an unsuccessful attempt at a political career while in Missouri as well. In 1859, Gilpin's early intuition about gold in Colorado proved correct, and the region suddenly became the target for thousands of eager and hopeful prospectors in the ensuing Colorado Gold Rush. That year, Gilpin published a futurist history of the region, called The Central Gold Region, in which he wrote, "the destiny of the American people is to subdue the continent". In the book he predicted that the Mississippi River valley would become the center of western civilization with the new settlement of Denver as its capital, based partly on its location near the 40th parallel north. In the book, Gilpin envisioned that all the great cities of the world along that latitude would eventually be linked by railroad