Old State Capitol State Historic Site is at 6th and Adams sts. Begun in 1837, the building served as Illinois' fifth statehouse 1839-76. It was the scene of three of the four Illinois constitutional conventions, and the stage for Abraham Lincoln's famous “House Divided” speech in 1858. After Lincoln's assassination, his body lay in state in the House chambers. The stark dolomite facade contrasts with the elegant interior dominated by an impressive double staircase.