Update: See the Biddle Mausoleum from March of 2015.
North of Bellefontaine Cemetery is Calvary Cemtery. Calvary has a couple of interesting mausolea I discovered last week while I searched for Dred Scott’s grave in vain. The Biddle Mausoleum, which I garnered from its text panel on the front entry, was originally downtown but was moved with other graves after the infamous cholera epidemic. I don’t know if that is correct or not, but the two spouses interred here: Thomas Biddle, and Anne Mullanphy Biddle, represent the wedding of two prominent early St. Louis families.
The Mullanphy family has left a built legacy throughout the city, in buildings that reached out to immigrants: the Mullanphy Tenement, and the Mullanphy Emigrant Home. The mausoleum is in desperate need of restoration funds.
Update: I went back and revisited the Kerens Mausoleum in the spring of 2020.
I had never heard of the Kerens family, so I looked into their history in St. Louis. It turns out that it refers to Richard C. Kerens, a successful Irish-American, judge, railroad baron, ambassador, as well as other professions. He died in 1916, which would stylistically corroborate with the architecture of his august mausoleum.