Andrew Johnson became the first President to be impeached. The impeachment was led by Radical Republicans who opposed his moderate views in regards to the South. Johnson removed Secretary of War, Edwin Stanton, without approval of the Senate which violated the Tenure of Office Act passed by Congress which was enacted to keep Presidents from obtaining too much Executive power. This act by Johnson gave the Congress the means necessary to impeach. However, he was acquitted by a single vote.
This impeachment of Johnson is a strong connection of Genesis 22 and the shadow of which it points to, the crucifixion of Messiah. The word impeach comes from the Anglo French word 'empecher' which means to hinder or prevent. This traces back further to the Latin word 'impedicare' which means to fetter or entangle. Literally, the shackling of the feet. This points to the binding of Isaac seen in Genesis chapter 22. Just as Johnson escaped impeachment by a single vote, so too Isaac escaped death by a narrow margin (Genesis 22:10-12).