Catholics are more likely to credit Christopher Columbus with discovering America than are other U. S. citizens. Peter Smith of the Louisville Courier-Journal reports:
Eighty-seven percent of Roman Catholics credit Christopher Columbus with discovering America, according to a 2010 survey. But while majorities in other religious categories agree, it’s by smaller margins, especially among people of non-Christian religions and no religion.
Columbus, of course, was Catholic, and he even has a well-known Knights fraternity named for him. Maybe that helps with name recognition.
Have a look at the graph, too.