Van Lew also operated a spy ring during the war, called "Richmond Underground," including clerks in the War and Navy Departments of the Confederacy and a Richmond mayoral candidate. Van Lew reportedly convinced Varina Davis to hire Bowser as a household servant, enabling Bowser to spy in the White House of the Confederacy. Varina Davis adamantly denied ever hiring Bowser, although it would be unlikely she would have known of Bowser's real identity or admitted hiring her after the fact. Although Bowser used several pseudonyms during and after the war, making her contributions especially difficult to document, newly uncovered sources confirm her involvement in the Union espionage circle run by Van Lew. Van Lew's spy network was so efficient that on several occasions she sent Lt. Gen. Ulysses S Grant fresh flowers from her garden and a copy of the Richmond newspaper. She developed a cipher system and often smuggled messages out of Richmond in hollow eggs. Union commanders highly valued Van Lew's work; George H. Sharpe, intelligence officer for the Army of the Potomac, credited her with "the greater portion of our intelligence in 1864-65." General Sharpe recommended that the government reimburse Van Lew $15,000 because of the great expense she incurred in her efforts, including employment of spies. Because of the merit of her work, General Grant appointed Van Lew Postmaster General of Richmond for the next eight years.