The status and circumstances of slaves in the 1770s (and at many other times as well) were very different in different places and for slaves who did different things. The differences were, of course, not applicable to all slaves in all circumstances, but they are generally true.
Geography did play a huge role in determining slaves’ status and circumstances. This is mainly true because of the fact that there were many more slaves in the South, fewer in the Middle Colonies, and fewer still in the North. Slaves’ status and circumstances were generally worst in the South. In that region, there were so many slaves (more than half of the population in many areas) that whites were very worried about the possibility of slave uprisings. Slave codes in those areas were much stricter and harsher than in the other regions of the colonies. For example, slaves in the North were generally not prohibited from learning to read. Slaves in New England were allowed to have legal marriages. This is very different than the situation in the South where there was felt to be a greater need to keep slaves subjugated.
Within any given region, the status and circumstances of slaves varied depending on the jobs that they had. In general, it is said that the job of a field hand was much harder than the job of a domestic slave. Field hands generally had to do harder physical labor and got a lower quality of food (since domestic slaves often got to eat leftovers from the whites’ meals). It should be said, though, that some historians feel that field hands had somewhat easier lives in a way because they were in the company of other slaves rather than being under the watchful eye of the plantation owners’ family. Slaves who were artisans could often hire themselves out in their free time and make money for themselves.
Thus, slaves could have very different life experiences based on the region in which they lived and the kind of work that they did.