The white pelican in the Louisiana state flag bears the yellow-brown crown of the state's official state bird, the brown pelican. STAFF PHOTO BY TRAVIS SPRADLING ...

With the flags regularly appearing on scoreboards and celebrating throughout the events, it’s easy to spot their similarities, especially with colors like red, white, blue and yellow.

Flown by many protesters at the U.S. Capitol on Jan. 6, the Gadsden flag has a design that is simple and graphic: a coiled rattlesnake on a yellow field with the text "Don't Tread On Me." ...