Right side only?

[ssgtedusmc]

Yes, the Marine Corps button is the same button that the revolutionary Marines wore with subtle differences in the style of eagle, the stars, the anchor and number of lines in the background.

The extra wide chevron was worn up into the early 1930's on the dress blue uniform and the narrower chevron was worn as early as WWI on the shirt and service uniform. I had a group of documents, photos and medals of a Marine Sgt who enlisted in 1920 and retired in 1939. In the photos was one dated in 1930 showing him wearing the wide chevrons on both sleeves on his dress blue uniform and on an earlier photo it showed him wearing the narrow chevrons on his long sleeve khaki shirt.

[yellowwing]

Excellent! I knew our Dress Blues Buttons were old school. Pride and Legacy!

[ssgtedusmc]

Sgt Leprechaun posted some photos of a friend's Civil War Marine kepi that has a close up of one of the side buttons and you can see it looks very much like our current button.