As there was no art school in Montreal at the time, Sandham learned his craft from Fraser, as well as local artists Otto Reinhold Jacobi, Adolphe Vogt, and C. J.

One particularly challenging composite, consisting of more than 300 separate people, won an award at the 1878 Exposition Universelle in Paris.

[1] In 1877, he began doing illustrations for Scribner's Monthly, with his first piece accompanying an article by William George Beers.

All of these efforts led him to be named a charter member of the Royal Canadian Academy of Arts, founded in 1880.

[1] In 1882, The Century Magazine (the successor to Scribner's) sent him on assignment with Helen Hunt Jackson to Southern California to investigate the lives of Mission Indians.