From Wikipedia: Over time, Clemens became increasingly dissatisfied with Gerhardt's constant demands for funds and his lack of gratitude. Putting his disappointment aside, Clemens passed along Gerhardt's request to Adam Badeau, Grant's military secretary, to cast the death mask of the terminally ill President Grant. Grant's son Fred agreed to the request. After President Grant had died and the death mask had been cast, Gerhardt refused to give the mask to Grant's family, asserting that the mask was his personal property. Clemens was dismayed by Gerhardt's refusal, and intervened when the family threatened Gerhardt with a lawsuit. Clemens agreed to forgive all debts that Gerhardt owed to Clemens and his wife, an amount of $17,000, in return for returning the mask to Grant's family. It is not known if Clemens was aware at the time that Gerhardt had secretly made a second death mask of Grant.

In the mid- to late 1880s, Gerhardt received commissions for memorial statues in New Jersey, New York, Connecticut, Massachusetts, Vermont, and Pennsylvania. Gerhardt's wife gave birth to a son, Lawrence, in 1890. In the late 1880s, Clemens faced financial difficulties of his own due to investment failures. He closed his mansion in Hartford in 1891 and moved with his family to Europe. Gerhard's sole patron would no longer be able to help him find work. Gerhardt's commissions had decreased dramatically by 1891 and he eventually sought work as a draftsman and machinist. In 1897, Gerhardt was working for bicycle manufacturer, Pope Manufacturing Company in Hartford.

Gerhardt's wife died in 1897 succumbing to tetanus after being injured by a rusty nail. By 1906, Gerhardt had moved to New Orleans. In 1909, it was reported by the New Orleans Times Democrat that the famous sculptor was struggling financially and working as a manual laborer. By 1920, Gerhardt had moved to Shreveport, Louisiana, and was working as a tailor. Gerhardt died May 7, 1940, in Shreveport.