It’s one of the most frequent dollar bill symbols. There are 13 arrows, 13 olive branch leaves, 13 olive fruits, 13 stars above the eagle, 13 steps of the pyramid, and 13 bars on the shield.

This United States one dollar bill is a memento of Apollo 13. In April 1970, Apollo 13, which as intended to be the third human landing on the Moon, instead traveled around the Moon and back due to an ...