It may be a little off subject, but cotton mill workers in the south were indentured servants until very recently.
They lived in company owned houses, got paid in script that was only redeemable at the company store, had to go to the company doctors and denists. As Tennesse Ernie Ford sang
"they owed their soul to the company store"

There were many forms of indentured workers in the south until the late 1950's

All of the trades had indentured - apprentices- some still do. Just like your experience.