Memoir 1, Page 121, Alien Enemies Act of 1861

"Now there had been a space of forty days, prior to the passage of the Conscription Act, in which 'Alien enemies' (Union men) might leave"

As Woods writes here, the Confederate Congress passed the Alien Enemies Act of 1861 to take care of any Unionists still in the South. This law gave Unionists 40 days to leave under the threat of deportation or imprisonment if they stayed. Those who did choose to stay were expected to take an oath of loyalty to the Confederacy or be officially declared “alien enemies” and treated as an enemy of the country.