I recently acquired this group of items off of Facebook Marketplace. There were items belonging to 4 individuals, spanning the Civil War to WWII.
Going to focus on the group of items attributed to a father and son.
The father served initially with the Army, in the Aviation Signal Reserve Corps, from Jan 1918 to his discharge in Jul 1918.
Immediate following his discharge, he enlisted in the USMC, until his discharge in Aug 1919.
Overseas service spanned Nov 1918 to Jul 1919, with the 11th Regiment in France as part of the 5th Marine Expeditionary Brigade.
First up, his USMC Good Conduct Medal, with accompanying certificate: