This story was originally published in CAPTAIN AMERICA #64, and takes place shortly before Betsy Ross replaces Bucky as Captain America's sidekick.
Although I didn't read the old Captain America stories very much, I have noticed that there were sometimes prolonged periods between Betsy Ross' appearances in these comics. Making the character more important in the comics was actually a big change from the way things had been before.
The bad guy this time is called "The Acrobat". The first time Captain America reappeared in the 1960's, it turned out to be a bad guy with the same name who was disguised as Captain America.
Art is credited to Ken Bald and Syd Shores.
Reblogged from http://fourcolorshadows.blogspot.com/