In 1492, Columbus sailed the ocean blue, but back then English dictionaries, like the United States of America, did not yet exist and alternative spellings abounded. This is a difficult typo to pin down since there are so many names and other words containing this root. Most people know that it's Colombia, South America, and Columbia University or Ohio. Some know that Peter Falk played "Columbo" on TV. A few may even know that Colombo is the largest city and commercial capital of Sri Lanka. (Or yogurt.) Beyond that you may have to go exploring a bit more than usual. In OhioLINK there are four cases of "Christopher Colombus" (nine without the quotation marks), although some look like variants. A search on Colombus + Columbus finds eight results, but Colombia + Columbia a whopping 228. Clearly, those are not all typos, but some of them probably are. Such works definitely need to be inspected firsthand to be sure.
(Statue of Christopher Columbus in Columbus, Ohio, from Wikimedia Commons.)