Biography
William C. Rust was from Sussex County, Delaware. William C. Rust was one of six Sussex County, Delaware citizens 'charged with disloyalty' for Southern sympathies. He was held as a civilian political prisoner at Fort Delaware during the U.S. Civil War, detained without trial under the wartime suspension of habeas corpus, and is named among the fellow prisoners in the Rev. Isaac W. K. Handy's 1863–1864 prison diary, 'United States Bonds; or, Duress by Federal Authority.'
Additional source for this Civil War detention: John A. Marshall, American Bastile (1869), printed pages 292, https://archive.org/details/americanbastile00marsgoog/page/n305/mode/2up. This is a partisan retrospective account; its judgments should be read as attributed claims.