Dome Restoration Project Necessitates Rotunda Closure April 12 through April 28. Click here for more information.
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.