which president advocated for relatively quick and easy ways to bring the south back into the union was it lincoln or radical republicans

Abraham Lincoln

Explanation:

Abraham Lincoln wanted to be lenient to the South and make it easy for southern states to rejoin the Union. He said that any southerner who took an oath to the Union would be given a pardon. ... Under Lincoln's plan, any state that was readmitted must make slavery illegal as part of their constitution.

becasue in the south they disallowed slavery but in the north slavery was illegial this boilled into because mexico wanted slavery

hope this