He began working in his father's merchandising business in Bridgeville, and gradually expanded it to include lumber, grain, grist and saw mills, and a brick yard.

Perhaps the switch resulted from his devotion to the Union, but it also may have been due to a three time failure to receive the Democratic nomination for governor.

In the months leading up to the 1862 elections Cannon and incumbent U.S. Representative George P. Fisher feared they would be defeated by a combination of so many Republican voters off serving in the U.S. Army, and polling place shenanigans by stay at home Democrats.

Besides despising him for switching parties and supporting the hated abolitionists, they thought he had virtually won his office at the point of a bayonet.

Then the whole affair was repeated a year later, when federal troops supervised a special election to fill the seat of deceased U.S. Representative William Temple.

As if to emphasize the point the General Assembly even rejected Cannon's request to approve the Thirteenth Amendment, prohibiting slavery.

This act had been approved by neighboring border state Maryland, but Delaware's Democrats would refuse to pass this measure for another generation.