Yes, that isn't a typo. The confederates actually made it to Maine, which caused quite a stir for those New Englanders who thought they were safely away from the civil war fighting.
In June 1863, Lieutenant C.W. Read commanded a confederate ship named the Archer (a ship he had captured), which marauded off the east coast. He and his men intercepted American trading vessels and set about burning and scuttling them. Union forces were put on alert and at one point 40 ships were searching for them.
With Union vessels everywhere scouring the seas for him, Lt. Read decided on the audacious plan of sneaking into Portland harbor to steal a steam powered ship.
In the early morning of June 26, they passed into the port undetected. They failed in their pursuit of a steam ship, but decided upon the revenue cutter the Caleb Cushing. The Caleb Cushing was in port due to the recent death of their captain. As a result, the ship only had a skeleton crew on watch which was easily overcome by the rebel forces. The Caleb Cushing was a two masted sailing craft. The rebels were able to exit the harbor without being challenged.
By early morning, the alarm was raised and a group of union forces, including local men, were in hot pursuit.
Two key events worked against Lt. Read and his men being successful in their escape. First, the fact that shortly after clearing Portland Harbor the wind died down and they were nearly dead in the water. Second, the fact that in their rush to escape they failed to realize that they had plenty of gunpowder, but almost no ammunition. Had the wind been with them or they had adequate ammunition they would have almost certainly gotten away. The Caleb Cushing was armed with a 32lb gun vs. the 2 brass 6 lb guns of the union ships.
It wouldn't have been a fair fight, that is for sure.
Lt. Read and his men abandoned the Caleb Cushing and set it ablaze which culminated in the dramatic explosion of the gun powder stores. They surrendered and were incarcerated at Fort Preble in Portland.
Two of the union sailors in hot pursuit of the Caleb Cushing were my Great-great-grand uncles, Andrew Hanley Fuller and Collingwood Fuller. Both sailors served on the Caleb Cushing, but were not aboard at the time it was taken.
Andrew H. Fuller's obituary includes the details of the excitement of this event. Special thanks to my distant cousin, Marc Brouillette, for providing me a copy of Andrew Fuller's obituary and telling me about the story of Andrew's part in the capture of the confederates that took the Caleb Cushing.
To find more about the historic incident of the taking of the Caleb Cushing, I was able to find a variety of of archived articles from Geneologybank.com and at the Chronicling America Newspaper project from the Library of Congress.
If you find out that your ancestor was involved in a historical event, these resources make a great first stop to find out more first hand knowledge of the event and how it was viewed at that time in history.