Due to a special event taking place in the U.S. Capitol on Thursday, September 18, there will be no tours of the U.S. Capitol that day until approximately noon. The Capitol Visitor Center will remain open during this time, and guided tours in the Capitol Visitor Center will be available.
Before the Civil War, members of Congress grappled with the anticipated benefits of expansion into western territories. To inform legislative decisions that would affect the territories and their inhabitants, Congress relied on maps and reports of expeditions, such as those led by explorer John C. Frémont, a member of the Army Corps of Topographical Engineers. The subsequent expansion, however, ignited a passionate debate over the expansion of slavery, pitting the proslavery South against the antislavery North.