From the Richmond Daily Dispatch January 4, 1862:
Death of Lieut. Dunnott.
Our readers will remember that we published, two or three weeks ago, an account of the extraordinary escape, from the Washington prison, of Lieut. H. H. Dunnott, a gallant young officer who was captured by the enemy in the battle of July 21st. We are now pained to announce his death, which occurred at the house of a friend, near Winchester, on the 29th of December, after an illness of some six weeks. The gentleman who communicates this intelligence adds that his last days were spent in earnest religious devotion, and that there is reason to believe he died a Christian. Lieut. Dunnott was a native of Delaware. He belonged to the 27th regiment Virginia volunteers, and no man was more ardent in his attachments to the cause of the South. The story of his captivity and escape will form one of the incidents in the history of the war.
You can read more about Lieutenant Dunott at The Delaware Grays in the section Delaware Confederates. He enlisted in the 27th Virginia Infantry ten days after Fort Sumter was bombarded. He was buried in the Delaware section of the Stonewall Cemetery in Winchester, Va.
Whether or not it’s true that “Some friendly ladies in Washington, visited him in prison, fitted him out in female attire, in which disguise he escaped”, there were females imprisoned within the Old Capitol Prison. Wikipedia says there were prostitutes locked up; after Dunott’s death the southern spies Belle Boyd and Rose O’Neal Greenhow spent time there.
At The National Archives you can see a note from Lt. Dunott to Rose Greenhow. He is thanking her for a package of something that I’m not making out. 01-05-2012: The link above might not work, so if you go here and search for dunott, you should be able to find the note.