Originally Posted by T. A. Gardner

All of the pictures were taken in the US.

In the ones you marked "North Africa" note the house in the background (lower middle photo). It is shake sided and has typical American style rain gutters. It is also of wood frame construction. This is very rare in North Africa and even in Europe where houses tend to be build of brick, block, and concrete. Stucco or a similar finish would be expected.
I would say in those photos they were practicing beach defense as coastal artillery somewhere on the US Eastern Seaboard.

In the bottom photo note the truck. It is a 1 1/2 ton of a pre-war pattern that didn't see much overseas service. Nor did the M1897A2 / A4 gun shown. These are almost certainly all taken prior to mid 1942 at the latest. Also note the old M1917 helments and 1940 - 41 pattern uniforms being worn.