Seabrook was born on Edisto Island at his family's plantation in and he received his education at the College of New Jersey from which he graduated in 1812.

He owned Gun Bluff Plantation on Edisto Island and engaged in agriculture issues of the state.

For several years, Seabrook was the president of the South Carolina Agricultural Society and he stressed the need upon the farmers of the state for diversification of crop.

In addition, Seabrook wrote the History of the Cotton Plant and A concise view of the critical situation, and future prospects of the slave-holding states, in relation to their coloured population.

Seabrook wrote an essay in which he advocated keeping enslaved African Americans in stocks overnight "as a powerful auxiliary in the cause of good government.