In 1873, following her father's death, Kate moved onto the "Edgewood" estate, which later became the neighborhood of Edgewood, Washington, D.C.; her father had purchased the bulk of the estate in 1863 and constructed a mansion on it. She lived a very quiet life with her three daughters (according to the 1880 federal census), Ethel, Kitty, and Portia Sprague. After her son Willie committed suicide in 1890, at the age of 25, Kate became a recluse. She eventually lost her fortune and, to get by, resorted to raising chickens, growing vegetables and selling them door to door. She died in poverty in 1899, at age 58, of Bright's disease and was buried at Spring Grove Cemetery in Cincinnati, Ohio.