I assume that comes from the Germanic roots of English, where the tens are put after the units when counting from 13 to 99. Four and twenty blackbirds... etc.
Then there comes the continental vs British confusion on the meaning of half hour, e.g. half ten in England is half past 10. Halb zehn in German means half past nine!!!
I assume some Americanisms came from the German immigrants. Like waiting 'on' something that is not a table. To meet up; up where??? etc....