the Reconstruction era of military occupation of the South for 10 years from 1867 to 1877

Congress divided the South into five districts governed by military commanders, overriding President Andrew Johnson's veto.

Voter Registration and Eligibility: Army generals were tasked with registering voters, including black men and white men who took an oath of allegiance

.Disfranchisement of Confederates: Former Confederate officials and leaders were barred from voting, which allowed for the election of new state legislatures with substantial Black representation and Republican majorities

https://www.senate.gov/artandhistory/history/common/generic/Civil_War_AdmissionReadmission.htm

South. The following March, again over Johnson’s veto, Congress passed the Reconstruction Act of 1867, which temporarily divided the South into five military districts and outlined how governments based on universal (male) suffrage were to be organized. The law also required southern states to ratify the 14th Amendment

https://www.history.com/articles/reconstruction

20,000 federal troops were stationed across these districts. Their duties included registering voters—which for the first time included Black men—and ensuring their safety while voting.

THE RECONSTRUCTION ACTS 1867

When a supplementary act extended the right to vote to all freed men of voting age (21 years old), the military in each district oversaw the elections and the registration of voters. https://courses.lumenlearning.com/atd-monroecc-ushistory2/chapter/radical-reconstruction-1867-1872/