Sarah also founded the Baltimore Hebrew English Sunday School (before financial reasons led the family to relocate to New York City) and a small synagogue in Harlem (the Hand-in-Hand Congregation) in 1870.

[12][13] In 1853, Colonel John C. Frémont, who had made several trips exploring the west and had unsuccessfully tried to make daguerreotypes to document his group's journeys, invited the young artist to accompany him as he attempted to prove that a “central route” near the thirty-eighth parallel would be the best path for a planned transcontinental railroad.

[1] Solomon Carvalho would nearly die on that trip of scurvy, starvation and frostbite, and he and his friend Frederick W. von Egloffstein would be nursed back to health by kindly Mormons in Parowan, Utah and Salt Lake City, as Frémont and several other surviving members would continue to California.

Carvalho published his diary of the five-month journey, Incidents of Travel and Adventure in the Far West; with Colonel Fremont's Last Expedition (1860), possibly before Frémont's presidential campaign or to fulfill a promise made to Mormon leaders during his recuperation.

[16] After the American Civil War, Carvalho moved his family to New York City, but cataracts impaired his continuing portrait work by 1869, and would ultimately blind him.

He and Sarah remained active in New York's Jewish community, and he tried to harmonize modern scientific thought and the biblical story of creation found in the book of Genesis in his final years, although that work was never published.

[18] His son David Nunes Carvalho (1848–1925) would become a famous paper, ink and handwriting analyst and author,[19] with his forensic work acknowledged by Arthur Conan Doyle, although his testimony at the second trial of Alfred Dreyfus (that Major Esterhazy wrote the treasonous notes) would fail to acquit the accused officer.