William Cozens Siderfin
Silver Bow County
History of Montana, 1913

The able and influential businessmen of Butte have no finer 
representative than William C. Siderfin, manager of Hon. 
W.A. Clark's mining and real estate interests in Butte 
district and Wallace, Idaho with which interests he has 
been identified since 1896.  A native of Great Britain, 
he was born on July 4, 1863 in Lantrissant, Glamorganshire, 
South Wales.  His father, Thomas Siderifn, a retired farmer, 
died at his home in Newport, Shropshire, England, in December 
1907, aged eighty-seven years.  His mother, whose maiden name 
was Frances L. Cozens, died at Newport, Shropshire in 
January 1908, aged seventy-three years.

Brought up in his native country, William C. Siderfin 
received excellent educational advantages being graduated 
from one of the English colleges in 1881 and successfully 
passed the preliminary examination of the Incorporated Law 
Society of London in that year.  Not meeting with a 
satisfactory opening in his chosen profession and being 
ambitious and hopeful, he immigrated to Canada in 1884 
and for three years was associated with the Grand Trunk 
Railroad first being employed in the auditor's department, 
and later in the train service department.  Coming from 
there to Butte, Montana in 1887 Mr. Siderfin was for two 
years storekeeper for the Montana Union Railway.  
Accepting a position as storekeeper and bookkeeper for 
the Alice Gold and Silver Mining Company at Walkersville, 
Montana, he retained that position from 1889 to 1895.  
He made an extended visit to his old home in England and 
on his return to Butte in 1896 he entered the employ of 
W.A. Clark at the Butte reduction works.  During the 
first seven years of his employment there he was 
assistant assayer and chemist.  In 1904 he became 
Senator Clark's assistant general manager and proving 
himself efficient in the performance of his duties, 
he was made successor to A.H. Wethey, who resigned his 
position in January 1911.

At Butte Montana on January 10, 1900, Mr. Siderfin was 
united in marriage with Alberta A. Hammer, a daughter 
of John G. Hammer of this city and they are the parents 
of four children, all of whom were born in Butte: Dorothy 
Gwendolyn, born June 16, 1902; Evelyn May, born December 
10, 1905; Marion Jean, born December 26, 1909 and Eric 
Cozens, born September 2, 1912.