John W. MacKay signed 1870 dated California check - Western Mining Magnate - Autograph

John William Mackay (November 28, 1831 – July 20, 1902) was an Irish-American industrialist. Mackay was one of the four Bonanza Kings, a partnership which capitalised on the wealth generated by the silver mines at the Comstock Lode. He also headed a telegraph business that laid transatlantic cables and he helped finance the New York, Texas and Mexican Railway Company.

John William Mackay was born in Dublin to a working-class family. they had a dirt floor hovel shared with a pig. In 1840, the family emigrated to the notorious Five Points slum in lower Manhattan; his father died soon after. As a boy Mackay hawked newspapers such as the New York Herald, and later apprenticed at William H. Webb Shipyard to support his mother and sister. Read more at https://en.wikipedia.org/wiki/John_William_Mackay