Upon her return to the United States, she married Burton Harrison, a lawyer and American democratic politician, who was at one time the Secretary of President Jefferson Davis.

Some of her other works included, Golden Rod, The Story of Helen Troy, Woman's Handiwork in Modern Houses, Old-Fashioned Fairy Book, Bric-a-Brac Stories, Flower de Hundred, Miy Lord Fairfax of Greenway Court, The Homes and Haunts of Washington, The Russian Honeymoon, Sweet Bells Out of Tune, A Daughter of the South and Other Tales, Bar Harbor Days, and An edelweiss of the Sierras, Golden-rod, and other tales.

[10] In September 1861, they sewed the first examples of the Confederate Battle Flag following a design created by William Porcher Miles and modified by General Joseph E. Johnston.

[12] She later met her future husband, Burton Harrison (1838–1904), a private secretary for Confederate President Jefferson Davis, and helped win his release from Fort Delaware after the war's end.

Their wedding breakfast was at Morrisania, the country home of her uncle, Gouverneur Morris Jr.[13] Burton Harrison held various public offices while Constance spent her time writing and being involved in the city's social scene.

[citation needed] Among her other contributions to American literature, Harrison persuaded her friend Emma Lazarus to donate a poem to the fundraising effort to pay for a pedestal for the Statue of Liberty.

[14] In 1871, the Harrisons first visited Bar Harbor, Mount Desert Island, Maine, staying at the cottage of Captain Royal George Higgins.

[17] "Sea Urchins" was the center of hospitality during the Gilded Age in Bar Harbor and she entertained many noted visitors there, including friend and neighbor James G. Blaine, who lived at "Stanwood".