First Session of the Thirtieth Congress--Mexican War--"Wilmot
Proviso"--Campaign of 1848--Letters to Herndon about Young Men in
Politics--Speech in Congress on the Mexican War--Second Session of the
Thirtieth Congress--Bill to Prohibit Slavery in the District of
Columbia--Lincoln's Recommendations of Office-Seekers--Letters to
Speed--Commissioner of the General Land Office--Declines Governorship of
Oregon