Charleston, South Carolina
In 1832, South Carolina passed an ordinance of nullification, a procedure by which a state could, in effect, repeal a federal law; it was directed against the most recent tariff acts. Soon, federal soldiers were dispensed to Charleston's forts, and five United States Coast Guard cutters were detached to Charleston Harbor "to take possession of any vessel arriving from a foreign port, and defend her against any attempt to dispossess the Customs Officers of her custody until all the requirements of law have been complied with." This federal action became known as the Charleston incident. The state's politicians worked on a compromise law in Washington to gradually reduce the tariffs.

Q: After South Carolina passed an ordinance of nullification, who was sent to Charleston Harbor?
five United States Coast Guard cutters