Dawn T: “I’m not sure this what I remember as a kid that was called American cheese that had the consistancy of cheddar or colby and quite firm, brittle, and broke easily. ”
 
seafarer john: “A somewhat more expensive,  and much superior, product was  available… it always came in wedges cut from a wheel of the product. As I remember it ranged from white to yellow in color, was more or less crumbly…”
 
Could this be what we used to call “brick cheese”, something you don’t see any more? That was either yellow or orange, slightly crumbly and a little milder than a mild cheddar.
 
And, around here (NE PA) we get a sharp American called Cooper cheese. It’s not bad, soft and creamy with a bite.