How did David Walker build an argument against slavery and in support of abolition?

Having witnessed slavery and racism, he wrote an 1829 pamphlet, Appeal to the Colored Citizens of the World that urged African Americans to fight for freedom and equality. Walker was decried for inciting violence, but also changed the abolition movement

Explanation:

The goal of the Appeal was to instill pride in its black readers and give hope that change would someday come. It spoke out against colonization, a popular movement that sought to move free blacks to a colony in Africa. America, Walker believed, belonged to all who helped build it.

the mexican-american war was a conflict between the united states and mexico, fought from april 1846 to february 1848.