People thought that an alien invasion was happening
Answer:
The imaginary line of Demarcation was drawn from the north to the south through the Atlantic Ocean, splitting it between Portugal and Spain.
During the ensuing decades, the abolitionist movement grew in Northern states, and Congress regulated the expansion of slavery as new states were admitted to the Union. Britain banned the importation of African slaves in its colonies in 1807 and abolished slavery in the British Empire in 1833.
