Actually the Independence was a CVL, a light carrier as opposed to a CVE or escort carrier. The Independence class consisted of 9 ships I believe, I’m working from memory here, and they were built on cruiser hulls. They could keep up with the big fleet carriers but they carried about half the air group of a fleet carrier, maybe 36-42 birds. The CVEs could only operate maybe 12-16 aircraft.
Cruiser hulls=FDR’s idea, but met with stiff resistance in Washington.