Certain acts of congress, enacted during the progress of the civil war (1801 and 1802) in the exercise of the war powers of the government and meant to strengthen its hands and aid in suppressing the rebellion, which authorized the seizure, condemnation, and forfeiture of “property used for insurrectionary purposes.” 12 U. S. St. at lifirge, 319, 589; Miller v. U. S.. 11 Wall. 208, 20 L. Ed. 135; Semmes v. U. S