In Ballston Spa West gradually acquired nine water-powered mills on Kayaderosseras Creek by 1879 manufacturing cotton, paper, and paper bags. West was called "The Paper Bag King" because he was one of the first men in the country to manufacture paper bags at a time when most bags were made from cotton. In 1869, he and the few other bag manufacturers in the country joined with Francis Wolle, inventor of the first paper bag machine, to form the Union Paper Bag Machine Company. Its only purpose was to "buy and fight patents." This early trust was highly successful, as each member had access to all of the earliest paper bag patents and agreed not to compete with each other. West manufactured bags from manila paper made of inexpensive jute butts from India. Thus, he was able to sell them at a much lower cost than cotton sacks. They became extremely popular, and he sold millions per week. His paper bag factory in Rock City Falls was one of the first in the country to manufacture bags with machinery. The success of his bags compelled West to purchase or build additional paper mills. By 1880 his mills consisted of the Union, Union Bag, Island, Eagle, Pioneer, Glen, Empire, Excelsior, and Middle Grove Upper and Lower Mills, all situated on the Kayaderosseras Creek in Milton. He purchased his largest mill in the town of Hadley, New York on the Hudson River. West sold his paper mill empire to the Union Bag & Paper Company in 1899 for $1.5 million. He also served as President of the First National Bank of Ballston Spa from 1879 until his death.
West married Louisa Rose in England. The couple had six children, three of whom lived to adulthood. George, Walter S., and Florence L., who married D. W. Mabee.
He was known as a philanthropist, donating funds to build a museum in Round Lake, New York, a Methodist church in Ballston Spa, and making liberal contributions towards the two soldiers' monuments in Saratoga County, in Ballston Spa and Schuylerville. In 1901 West died at his mansion in Ballston Spa with a fortune that would today be worth $75 million. His wife predeceased him by seven months. They are buried in the Ballston Spa Village Cemetery. His original residence in Rock City Falls still stands on Route 29 as The Mansion Inn, now listed on the National Register of Historic Places.
