One hundred fifty years ago today, just two days after taking command of Fort Monroe in Hampton, Virginia, Lowell’s Ben Butler made a decision that changed history. Sometime during the night of the 23-24 of May, three slaves who had been digging gun positions for the Confederate forces besieging Fort Monroe, escaped and showed up at the fort asking for asylum. What to do with slaves who came into custody of the Union Army was a dicey proposition, fraught with legal peril. While it would be absurd for the Union Army to send such slaves back to their Confederate owners, neither could they set them free. To do so would be to inflame the non-abolitionist sentiments in the North and would also likely tip the three border states, Maryland, Kentucky and Missouri into the Confederacy.

With no guidance from higher headquarters, Butler drew upon his legal training to make his decision. The long-time Lowell lawyer knew that under the laws of war, if one side came into possession of personal property of the other side that was being used to advance that side’s war activities, it was proper to keep that property as “contraband of war.” Butler therefore decided that slaves that came into the custody of him command would be held as contraband of war. He telegraphed his decision to Washington and his policy was soon adopted throughout the Union Army. This precipitated a flood of escaped slaves streaming into Union lines and began influencing Lincoln’s thinking on the subject of slavery, an evolution that resulted the following year in the Emancipation Proclamation.