The Washington University Hilltop Campus Historic District was the site of the 1904 Louisiana Purchase Exposition and the 1904 Summer Olympics.

Many of the exposition buildings were temporary in nature, but a number of permanent structures were built and are used by Washington University, which calls this area the Danforth Campus.

The district includes more than fifty structures, of which twenty are in the Collegiate Gothic style.

The Collegiate Gothic structures form a unified composition, despite their construction over a fifty-year period.

This is attributed to a style guide compiled by architect James P. Jamieson, who defined the use of red granite, green slate shingles and copper flashing and drainage details.