Answer:
I believe it was justified. First, let's remind ourselves why Andrew Jackson was impeached. In 1968, Andrew Jackson was impeached for violating the tenure of office act. The tenure of office act was created to limit the president's ability to remove some office-holders from power. Originally, this act was vetoed by Jackson, but the veto was overturned by Congress.
Andrew Jackson attempted to remove the secretary of war, Edwin Stanton, which was ironic because this act was made to protect people such as Stanton. The majority of the senate did vote to convict, but due to the fact that impeachment convictions take a constitutional majority (2/3's), Jackson was acquitted.