The Jamestown colonists wanted to set up a big forced-labor slave plantation like the Spanish, but couldn't because there was no gold. The only thing of value was food and crops and if you tired to force growing this the productivity fell to nothing. From [1] ,"... It was Smith[the guy who ran Jamestown] who was the first to realize that the model of colonization that had worked so well for Cortés and Pizarro simply would not work in North America. The underlying circumstances were just too different. Smith noted that, unlike the Aztecs and Incas, the peoples of Virginia did not have gold. Indeed, he noted in his diary, “Victuals, you must know is all their wealth.”..."
They even set up a governor(fake king) with a bunch of nobles who owned large land tracts and then planted them with settlers but with the only thing valuable being land forcing them to work it was problematic when there was so much free land. As you've said they would run off any chance they got. From the book,"...Just as the attempt to impose draconian rule in Virginia failed, so did the plans for the same type of institutions in Maryland and Carolina. The reasons were similar. In all cases it proved to be impossible to force settlers into a rigid hierarchical society, because there were simply too many options open to them in the New World. Instead, they had to be provided with incentives for them to want to work..."
[1]Daron Acemoglu, James A. Robinson - Why Nations Fail: The Origins of Power, Prosperity and Poverty (2012)
Indentured servitude was about the best they could do. It gave the slaves incentive to work, to wit, they'd be free eventually. They were often stolen in the first place, so there wasn't much they could do but work. They started bringing black slaves over in 1619 after they had too many problems with white slaves starting in 1607. The black and white slaves would often run away together, but the plantation owners paid Indians to bring them back at first.
melmagazine.com
