How much did the flood of cheap white, particularly Irish, labor influence the end of African slavery in USA?

I would credit that for the Northern Industrial Strength (in part) and the Thousands of Irish fighting for the North that helped to end the war. Slavery was already abolished in the North by the time of mive Irish Immigration. The South wasn't going to give up slavery without a fight. They had much less industry than the North so I don't see industrialization and Immigration directly affecting Slavery in the South.