In this passage taken from "Chapter II: Influence of Lincoln." written by Jane Addams we can tell the author is comparing two architecture structures. One is St. Peter's Basilica which is an Italian Renaissance church located in the Vatican City, that also serves as the papal enclave within the city of Rome; and the other is the Wisconsin State Capitol. Since On page 29 he says "I stood under the great white dome of Old Abe's" and then proceeds to describe his feelings.
The Wisconsin State Capitol is located in Madison, Wisconsin and it houses the chambers of the Wisconsin legislature along with the Wisconsin Supreme Court and the Office of the Governor.
The author makes a statement about how both buildings share a similar design and shape. This is defined when the author mentions about a "dome" and about the building that he is in having a "modest curve". It is also mentioned that it captures him, which can happen when a person stands below such magnificent architectonic work.