I worked at Unit 5 in Rockville Maryland/DC area in 1966-1967. The full basement was where they stored the big burlap bags of potatoes - a ton or two iirc.
My first job was carrying bags up and running them through the peeler. Then the wash sink, the shoe-stringer and the first blanch vat. After cooling they'd be fried later at a higher temp in good tasty beef grease. This was back in the day when the burgers went from 15 to 18 cents and the starting pay was $1.15.
I believe they switched to 10-pound bags of frozen fries about the time I moved on. I got a job helping on a tree cutting crew for $2.35 an hour plus 1.5x for overtime.