There was a major shift in allegiance of african americans from the party to the party.

The answer is: Republican - Democratic

In the past (around the time when Lincoln held the leadership position) , the republican party was the platform that advocated for the establishment of slavery. The major shift happen in mid industrialization due to the amount of social  programs that offered by the democratic party.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.