Complex sentence: Demands for a fitting national memorial had been voiced since the time of Lincoln's death, and in 1867, the Congress passed the first of many bills incorporating a commission to erect a monument for the sixteenth president.
Split into simpler sentences: Demands for a fitting national memorial had been voiced since the time of Lincoln's death. In 1867, the Congress passed the first of many bills incorporating a commission to erect a monument for the sixteenth president.