201 Lafayette St. – Baton Rouge LA (built 1927; currently Hilton Baton Rouge Capitol Center; also Capitol House Hotel; architect: Edward Nield)
A favorite place to stay of Louisiana Governor and US Senator Huey Long, the Heidelberg was built in 1927 and listed on the National Register of Historic Places in 1982.
The Baton Rouge Digital Archive (from the East Baton Rouge Parish Library) has several Heidelberg postcards, pictures, and menus scanned and posted:
Hotel breakfast menu, date unknown (click for full menu):
1927 (click for full image):