Why did Thomas Jefferson believe in 1785 that African Americans should be colonized elsewhere?

Explanation:

In 1779, as a practical solution, Jefferson supported gradual emancipation, training, and colonization of African-American slaves rather than immediate manumission, believing that releasing unprepared persons with no place to go and no means to support themselves would only bring them misfortune. In 1784, Jefferson proposed a federal law banning slavery in the New Territories of the North and South after 1800, which failed to pass Congress by one vote.In his Notes on the State of Virginia, published in 1785, Jefferson expressed a belief that slavery corrupted both masters and slaves alike, and that gradual colonization would be preferable to immediate manumission.  In 1794 and 1796, Jefferson freed two male slaves; they had been trained and were qualified to hold employment.Most historians believe that after the death of his wife Martha, Jefferson had a long-term relationship with her half-sister, Sally Hemings, a slave at Monticello. jefferson allowed two of Sally Hemings's surviving four children to "escape"; the other two he freed through his will. In 1824, Jefferson proposed a national plan to end slavery by the federal government purchasing African-American slave children for $12.50, raising and training them in occupations of freemen, and sending them to the country of Santo Domingo. In his will, Jefferson also freed three other men.In 1827, the remaining 130 slaves were sold to pay the debts of Jefferson's estate

there are no mutiple choices here

a countries leader should be motivated by the common good of the country.