Marcus Brunswick operated a merchandising and freighting business in Las Vegas, New Mexico. He also ran a second outfit in Lincoln, N.M. He was involved in shipping hardware, livestock, food, and other items to businesses and ranches throughout New Mexico. He supplied corn to United States army forts in New Mexico. Business interests included financing livestock purchases and mining ventures. Brunswick also offered paralegal services including the preparation and witnessing of deeds, mortgages, loans, and powers of attorney. He is buried in the Charles Ilfeld family plot in Las Vegas, N.M.
From the guide to the Marcus Brunswick Business Records, 1872-1927, (University of New Mexico. Center for Southwest Research.)