Nelson was an important settler of the
St. Croix River valley. When arriving in Stillwater, he initially built a store and established a mercantile business, which he ran for eleven years. Realizing that land development, rather than fur and trading, would be more prosperous, Nelson and Churchill laid claim to large tracts of land near the
St. Croix River in 1845 and purchased the land from the
United States General Land Office in 1849. By the summer of 1847, Nelson was shipping rafts of
white pine lumber hundreds of miles downriver to St. Louis, and in the summer of 1848, he and Churchill together purchased an area of timberland. Nelson entered the lumber business in earnest on February 7, 1851, as one of the corporators of the St. Croix Boom Company organized by the Minnesota Territorial Legislature. In 1852, Nelson and associates
David B. Loomis and Daniel Mears (Nelson, Loomis and Company)
platted what is now
Bayport. The steam-powered sawmill operated from 1853, the year Nelson left the mercantile business, He operated the mill infrequently over the next ten years and sold the property in 1868. in Stillwater, Minnesota, built on land donated by Nelson and his business partner Riding a boom in
real estate speculation and soaring land prices, Nelson and Churchill deeded of land in January 1857 to St. Paul real estate salesman Robert F. Slaughter, half of which Slaughter deeded in turn to Hilary B. Hancock. Along with their wives, the four platted the area of nearly 500 lots on June 15, just months before the onset of a worldwide financial crisis known as the
Panic of 1857. Amid a collapsing real estate market and with speculation screeching to a halt, the value of the now-platted and mostly unsold land plummeted to practical worthlessness. Months after the Panic began, Levi Churchill died and ceded his estate to his wife Elizabeth. Demoralized by deflated land prices, Slaughter and Hancock forfeited their claim to the lots. In early April 1867, hoping to spur development and drive demand for nearby lots they owned, Nelson and Elizabeth Churchill offered to sell the city of Stillwater an entire block of land for a token amount of $5 () with no strings attached for the construction of a courthouse. and the courthouse building prompted development of the area, which Nelson would not live to see. In other business ventures, Nelson was a corporator of the Minnesota Mutual Fire Insurance Company in 1848. In 1853, he became one of the corporators of the Louisiana and Minnesota Railroad Company, the
St. Paul Fire and Marine Insurance Company, and the Minnesota Western Railroad Company. In 1854, a
stock company consisting of Nelson and others published Stillwater's first newspaper, the
St. Croix Union – a Democratic-leaning, weekly periodical which was printed until 1857. On January 27, 1867, Nelson became a corporator of the Stillwater & St. Paul Railroad. == Political career ==