Pokestops are, in general, "street furniture". While most of these were initially Ingress sites, and many others have been added (notably Starbucks and Sprint stores):
Churches, temples (many faiths), zen centers. I no longer live near a Sikh house of assembly, nor a mosque, so I don't know about coverage of all faiths.
Architectural details (gargoyles, mosaics, art deco terra cotta tilework, cupolas, etc.)
Public artworks, especially in vest-pocket parks.
Subway stops/train stations, etc.
Now, I am not aware of any statues, here in NYC, CT, PBCo., which commemorate events or personalities who contributed to the US civil war on the losing side. So I do not know if they are Pokestops. I suspect not.
I would like to know if Pokemon Go has lessened gang graffiti and neo-Nazi graffiti on "street furniture", especially given that children are increasingly visiting these public markers.
Surprising to me, some bars (albeit with architecturally-notable facades) are Pokestops.