On the outside, the Capitol remained largely unchanged during this period. Inside, however, various artistic projects were undertaken to improve the Capitol's interior. In the rotunda, Constantino Brumidi began painting the 300-foot-long frieze in 1878 with scenes from American history. Sculpture was originally intended for the frieze, but Brumidi was able to achieve a similar effect with paint.

After the death of Vice President Henry Wilson in 1875, the Senate commissioned a bust of its deceased presiding officer (the vice president is President of the Senate), displaying it in the room where Wilson had died. This launched a program to commission busts of all former vice presidents for the Senate wing. The House, in a similar tribute to its history, began commissioning oil portraits of former Speakers in 1911.