Why was the reconstruction act of 1867 so important

The reconstruction act of 1867 was important because among other things, black people, including those who had recently been freed  received the right to vote, hold political offices, and become judges and police chiefs.

They held positions that formerly belonged to Southern Democrats. Many in the South were aghast. President Johnson vetoed all the radical initiatives but congress (republicans) overrode him each time. It was the Radical Republicans who impeached President Johnson in 1868. The senate by a single vote, failed to convict him but his power to hinder radical reform was finished.