Answer:
The two ideas that the passages share are:
Lincoln was initially hesitant about allowing African Americans to join the Union Army due to concerns about the border states, but ultimately made the decision and it proved beneficial to the Union.
Congress did not support Lincoln's plan to allow states to rejoin the Union easily.
Therefore, the correct answers are:
Lincoln's decision to allow African Americans to join the Union Army was beneficial to the Union.
Lincoln was concerned about angering the border states.
Congress did not support Lincoln's plan, which would allow states to rejoin the Union.