He started law school at Harvard College, but didn't finish due to ill health.

He moved to live on his brother Edwin's farm in Prairie Ronde, Michigan, to recover.

[3] Lothrop was a candidate for U.S. Representative from Michigan's 1st congressional district, losing to Republican William Alanson Howard in 1856 and to Bradley F. Granger in 1860.

Lothrop's daughter, Emily Anne "Nan" Lothrop (1860–1927), married Baron Barthold Theodorevitch von Hoyningen-Huene (1859–1942), a Baltic nobleman and military officer, and their son was the noted fashion photographer George Hoyningen-Huene.

His daughter Elizabeth, a noted fashion designer, His brother-in-law, Oliver Ames Jr., was affiliated with the Union Pacific Railroad.