Based on the chainwheel design you have purchased a CCM. They are/were a Canadian company that makes/made everything from hockey helmets to, well, bicycles.

They are cool old bikes with 3 piece cottered cranks, not unusual during the time it was made in the late 60s/early 70s. If you were wondering about value, unfortunately the paint job robs most of it from you, but a good valuation as-is would be in the $30-$40 range. If it had the original paint (and decals) even if it was all scratched up you could probably triple that number.

EDIT: It’s definitely a CCM, and $15 was a very good deal. Back in the day when that bike was made very few companies actually gave their bikes model names. Raleigh, Schwinn, and a couple of others did, but thats about all. It’ll be hard to track down more info on it unless you can find an old CCM catalog or something.