Habeas corpus allows a party to claim that someone is being unlawfully detained or imprisoned - a process to demand that a judge on release them from custody. Temporarily suspending it would allow for rounding up known traitors as "prisoners of war, spies or aiders or abettors of the enemy" "in cases of rebellion or invasion", without legal battles and public controversy over claims of "unlawful detention".

>DECLAS COMING?

>Are you ready to see arrests?

>Do conditions need to be satisfied to authorize?

>What former President used the military to save the republic and what occurred exactly?

>Biggest drop to ever be provided…

I, ABRAHAM LINCOLN, President of the United States, do hereby proclaim and make known to all whom it may concern, that the privilege of the writ of habeas corpus is suspended throughout the United States… and that this suspension will continue throughout the duration of the said rebellion…

…during the present insurrection… by the authority of the President of the United States, military, naval and civil officers of the United States [may] hold persons under their command or in their custody…

https://archive.vn/20200326180929/https://www.nytimes.com/1863/09/16/archives/presidents-proclamation-the-habeas-corpus-suspended-throughout-the.html