Orthwein emigrated to the United States in 1860, arriving in Lincoln, Illinois, to work as a salesman.[1] In 1862, he joined his brother in St. Louis, Missouri, to work for his grain commission business, Haenshen & Orthwein.[1] Meanwhile, he served in the Union Army during the American Civil War of 1861–1865.[1]
After the war, Orthwein resumed work for Haenshen & Orthwein.[1] By 1870, he worked for his brother's grain shipping firm, Orthwein & Mersman (co-founded by Charles F. Orthwein and Joseph J. Mersman),[3] up until 1879.[1] The firm shipped grains to Europe from St. Louis, via New Orleans, Louisiana, and Galveston, Texas.[1] In 1879, it became known as Orthwein Brothers,[3] and it was in business until 1893.[1]
Orthwein founded the William D. Orthwein Grain Company in 1893.[1] It was "the oldest grain firm in St. Louis."[1] He hired his son Frederick to work with him until 1900, when he retired.[1]
Orthwein married Emily H. Thuemmler on June 9, 1870.[1][5] Around 1900, they built the Orthwein Mansion at 15 Portland Place in St. Louis and lived there for a quarter-century.[5]
Orthwein was a member of the Log Cabin Club and the Union Club, two private members' clubs in St. Louis, Missouri.[1] He donated to the Mullanphy Emigrant Relief Fund.[1]
Death
Orthwein died in 1925,[6] leaving an estate of about US$2 million
(about $34,700,000 today[7]).[6]