The American Crusader is a fictional character, a superhero who originally appeared in "Thrilling Comics" #19 (Better Publications, 1941). The character was revived in the Modern Age in "Femforce" #59, by AC Comics, and in "Tom Strong" #11, by Alan Moore and Chris Sprouse.
Better Publications was formed in 1941.
It's never mentioned when the company was formed, so we don't know. It's difficult because the text says (Better Publications, 1941), but that just means they released that comic in that year, not that they were formed in that year.