what kind of freedom does douglass have over his own employment after learning to calk ships?

After learning the trade of caulking, Douglass is free to seek his own employment, make contacts and earn his own money. He had leisure time and worked as he was willing.

There I was immediately set to calking, and very soon learned the art of using my mallet and irons. In the course of one year from the time I left Mr. Gardner's, I was able to command the highest wages given to the most experienced calkers. I was now of some importance to my master. I was bringing him from six to seven dollars per week. I sometimes brought him nine dollars per week: my wages were a dollar and a half a day. After learning how to calk, I sought my own employment, made my own contracts, and collected the money which I earned. My pathway became much more smooth than before; my condition was now much more comfortable.