Why was Yankee Doodle dandy?

Answer 1

Because he stuck a feather in his cap!

The word dandy made its first appearance in a Scottish border ballad about 1780, but probably not with its more recent meaning. It was perhaps a shortened form of jack-a-dandy, (Encyclopaedia Britannica 1911) and it became a vogue word during the Napoleonic Wars. In the slang of the time, a dandy was differentiated from a fop in that the dandy's dress was more refined and sober.

In the 21st century the word "dandy" has become a jocular adjective meaning "fine" or "great," and is often used sarcastically. However, sometimes a well-dressed and self-absorbed man is still referred to as a dandy.

Answer 2

Yankee Doodle was dandy because he was handy with the girls.
Now Yankee Doodle went to town, a riding on a pony, stuck a feather in his hat and called it macaroni, Yankee Doodle keep it up Yankee Doodle dandy, mind the music and you step, and with the girls be handy

Answer 3

he callled it macaronni!