At war's end in 1864 Mitchel moved to New York and edited "New York Daily News". In 1865 his continued defence of southern secession caused him to be arrested in the offices of the paper and interned at Fort Monroe, Virginia, along with Jefferson Davis and Senator Henry Clay. His release was secured on condition that he left America. Mitchel returned to Paris where he acted as financial agent for the Fenians. But by 1867 he was back in New York resuming the publication of the "Irish Citizen".