2" tube and a drill are all you need to make a nice flag holder for the hitch.
(and vice helps,,,,,, Yeah, you need a vice too)


"IF" you have the step drills or other drill bits it helps but harbor freight is everywhere. lol
I use a cut off wheel to cut some tube and make 2 different types, but the simple one is just drilling the holes for the hitch pin, the flag pole size and pinning the flag with another hole.
I used Conduit for the flag it self and it's "super" durable. Interstate speeds are no problem. You can either latch pin, or nut N bolt the flag in place.
I like being able to un pin the flag and place it inside when needed so some jack wagon can't steel it or vandalize it. (good way to get shot)

 

CB antenna mount

 

Definitely had to fly the stars & stripes on Independence Day

Kind of want to find more excuses to string it up - I flew it today with the excuse of Juno Probe's successful entry into Jupiter's orbit (go America and go NASA by the way)