The Confederates, commanded by Colonel Joseph J. Cook, could not get a boat to Harriet Lane in a timely manner, and the Union ship left the bay.

At the expiration of the truce, Union troops landed in Galveston and raised the United States flag over the city.

Under international law of the time, a blockade needed to be effective in order to be legal, and in December, HMS Desperate visited Galveston and saw no US Navy presence.

William McKean, commander of the Gulf Blockading Squadron, doubted the accuracy of the British report but forwarded the information to the United States Secretary of the Navy.

[2] Under the supervision of Major General John B. Magruder, Confederate forces under W. W. Hunter had been placing artillery batteries, digging trenches, and obstructed harbor channels to ready the defense of Galveston.

[5] In August, Union Admiral David Glasgow Farragut ordered Commander William B. Renshaw[6] to destroy blockade runners and capture Galveston if practicable.

After waiting in vain for Confederate messengers to reach the ship and reply, a boat of officers from Harriet Lane was sent to shore, where they met with Cook, who agreed to send a delegation to the Union fleet to discuss surrender terms.

[17] Cook's messengers reached and boarded Westfield,[8] and Renshaw demanded immediate surrender, and threatened a further attack if it was not agreed to.

The Confederates declined and reminded that Renshaw would be responsible for any damage to private property or civilian fatalities in the case of an attack.

A detachment of 150 men led by the commander of Harriet Lane raised the United States flag over the city,[19] as there were no longer any Confederate defenders there.

[20] Lack of cooperation from Major General Benjamin F. Butler resulted in difficulties in getting Union infantry to hold Galveston.

Renshaw was killed by an explosion while scuttling Westfield, and Harriet Lane was captured; the Confederates regained control of Galveston.