The impeachment of president andrew johnson was due to

was due to violation of the Tenure of Office Act.

Explanation:

Andrew Johnson's impeachment began in 1868 on charges of violation of the Tenure of Office Act, which made the resignation of certain cabinet posts conditional upon prior Senate approval. Johnson had fired Secretary of Defense Edwin M. Stanton, a radical Republican, without prior consultation with the Senate.

answer; /// i do believe that its napolean's conquest of spain;