guess would be that Maceo became a given name in the African American community in honor of the Cuban general Antonio
was an Afro-Cuban and was known as "The Bronze Titan."http://www.afrocubaweb.com/maceo.htm
Of course the surname Maceo would not be pronounced as may-say-oo in Spanish, but that's probably not significant. Most African-Americans who read about Antonio
Maceo would not have been familiar with how Spanish is pronounced, and so would have said the name the way they thought it looked in English. There are plenty of other examples where parents have found a foreign name in print that they liked the looks of and have used a different pronunciation than that of the original language. The American actor Ian
Ziering, for example, pronounces his first name to rhyme with Brian
, because his parents discovered Ian
in print and did not realize that the traditional pronunciation was "EE-un" instead of "EYE-un".
I don't have my surname dictionaries handy at the moment so can't look up the derivation of the surname, but will try to remember to do so tomorrow.