During my genealogy work, I have encountered several cases where streets or parts of streets where my ancestors lived no longer exist. The most recent case was a street named Stillwater Avenue that didn't show up on a Google search. I had to find an old Dayton map with a street cross-reference, in this case from 1945, that included Stillwater Avenue and found that it was replaced with the current, southern-most section of Riverside Drive, where it terminates at the bridge to cross the Great Miami River and become Patterson Blvd on the southern side.
The map shows that Riverside Drive followed the river back then all the way until it terminated, instead of the current route where it follows the river until it goes under I-75, then bends right, away from the river, to line up with Patterson Blvd. That land east of the current Riverside Drive is where Temple Israel and the Korean War Veterans Memorial now stand.
You can download a PDF of the 1945 map at this link.