Silkman was graduated at Yale University in 1845, studied law, and after laboring as a journalist, was admitted to the bar in 1850, soon establishing a good practice.
Prior to the American Civil War, he caused much excitement by introducing resolutions against slavery in the New York diocesan convention of the Protestant Episcopal church.
In his childhood his father met with the loss of his property, and the son's preparation for college (entering Yale University in the Sophomore year) was thereby deferred.
Litigation ensued, which resulted in his release, and he gave much of his time afterwards to the investigation of cases alleged to be of a similar character,[2] including that of Clarissa Caldwell Lathrop, who detailed her confinement in A Secret Institution.
In January, 1888, he had a bout of pneumonia, from which he partially recovered, but heart failure resulted in his death, at a hospital in New York City, on February 4, 1888, in his 69th year.