In December 1845 he helped freedman Samuel Hawkins escape with his enslaved family of seven (owned by 2 masters) from slavery in Maryland. Although the slavecatchers caught the family on Hunn's farm, the local sheriff noticed a defect in the paperwork, and early in 1846 Delaware Supreme Court justice James Booth Jr. freed them based on a writ of habeas corpus sought by a fellow abolitionist (and lawyer) James Wales, and Thomas Garrett quickly called a coach to take them across the border into Pennsylvania. The displeased slaveholders then sued Hunn and Garrett for violating the Fugitive Slave Act in the U.S. District Court in the New Castle Court House. After a trial presided over by U.S. Supreme Court Chief Justice Roger B. Taney and District Judge Willard Hall, both Hunn and Garrett were convicted and fined heavily. Prosecutor James Bayard reportedly told Hunn the fines would not be imposed if he would promise not to continue his efforts to aid fugitives escaping from slavery, but Hunn "vowed never to withhold a helping hand from the down-trodden in their hour of distress." His land holdings and all his possessions were sold at sheriff’s sale in mid-1848. Although his family was left utterly destitute, Hunn continued his efforts to abolish slavery.