Built during 1859–67, it is one of the few well-preserved surviving works of Leopold Eidlitz, a leading mid-19th-century American architect, and was designated a National Historic Landmark in 1994 for its architecture.

The Gothic Revival structure was an expression of the city's sense of its significance as the United States expanded westwards.

[2] The cathedral is located in what is now downtown St. Louis, at the southeast corner of Thirteenth and Locust streets.

The main body of the church was built of Illinois sandstone, and its roof is of purple and green slate.

[6] Montana silver magnate Charles D. McLure, a St. Louis native, was revealed to be the anonymous donor of $50,000 toward constructing the cathedral (approximately $6.5 million today).