Andrew B. Hammond arrived in 1872 from New Brunswick, Canada to become a salesman for Bonner and Welch. He became an owner and managing partner in the Missoula merchandising store, Eddy, Hammond and Company (formerly Bonner and Welch) in 1876. Under Hammond management, a permanent and expanded structure was under construction in 1877, with several additions to follow. Careful attention to inventory and an aggressive business policy of locating branch stores throughout the trade area helped Eddy, Hammond and Company replace Worden and Company as the leading mercantile in western Montana.
Realizing that continued prosperity for Missoula would be enhanced by the arrival of the railroad, A. B. Hammond, C. P. Higgins, E. L. Bonner, Francis L. Worden, A. J. Urlin, and Washington J. McCormick were instrumental in bringing the railroad to Missoula. Bonner used his political influence to lay the commercial groundwork; Hammond set out ties and bridge timbers in areas he thought the rail line would run; Higgins and Worden offered the rail line choice lots throughout Missoula as did Urlin and McCormick with the intent that the railroad set up a station, repair shop, and divisional headquarters. With the gift of hundreds of lots to the railroad, Higgins and Worden hoped the lumber contract for ties, bridges, and buildings would be awarded to Worden and Company. The effort of all men helped attract the Northern Pacific Railroad, but the lumber contract went to Eddy, Hammond and Company.
The lumber was supplied from sawmills located in Hellgate Canyon, O'Keefe Canyon, the Bitterroot, and Thompson Falls. Crews cut massive amounts of timber. The Marent Trestle (pictured at right) constructed in 1883 near Evaro once was the highest and largest wooden structure in the world. The wooden trestle was short-lived as it was replaced by a steel structure in 1885.
In 1882 Hammond, Eddy, Bonner and other investors partnered to create the Montana Improvement Company, an enormous sawmill at Bonner. The Bonner mill supplied timber for the railroads as well as the Butte mines.
Though Bonner and Hammond amassed large fortunes in logging and other Montana investments, it was not without scandal. In 1884, the U.S. Attorney General B. H. Brewster questioned the excessive cutting of timber on the Flathead Reservation and in the public domain. For several years, Bonner and Hammond were accused of illegally logging public and tribal lands. Because of the threat of lawsuit, Hammond reorganized his holdings to lessen the impact of possible federal action. Eventually, the federal grand jury indicted the pair, but the threat did not slow timber operations. In 1887, Hammond helped found the Blackfoot Milling and Manufacturing Company, which took over the Bonner mill and eventually became one of the largest mills between Wisconsin and the Pacific Coast. Because of the indictments against Hammond, the Democratic Cleveland administration continued to push for strict interpretation of timber laws, but when the newly elected Republican administration took office, charges were soon dropped.
Once the charges were dropped, the Hammond managed Blackfoot Milling Company dramatically increased production. The Hammond managed Missoula Mercantile Company continued to prosper by aggressive marketing. The ongoing rivalry between Higgins and Hammond fueled the building boom in Missoula. The city of Missoula quickly spread south of the Clark Fork River. By 1890 Hammond had taken over the Missoula National Bank, ousting its founder and president, C. P. Higgins. Hammond changed the bank's name to the First National Bank of Missoula and erected a large four-story granite and stone building across the street from the Missoula Mercantile Company. In 1888 also across the street from the Missoula Mercantile Company, Hammond built a beautiful hotel, the Florence, in honor of his wife. Shortly after, he built the Hammond Building on the southwest corner of Higgins Avenue and Front Street. This four-story brick and granite castle-like building housed Hammond's offices and several commercial offices and stores.
Hammond controlled most of the area's banking, merchandising, transportation, and land development, even after his departure in 1892. After learning of the closure of the Higgins Western Bank caused by "the Panic of 1893", Hammond pledged assets of the Missoula Mercantile Company so that the First National Bank of Missoula would remain solvent. Both institutions survived the hard times. Hammond left management to Charles H. McLeod so that he could concentrate on building an empire of lumber, railroads, and ships on the West Coast. The largest of his ships was named Missoula. He died in San Francisco in 1934 at the age of eighty-six.
Though Hammond profoundly impacted the Missoula area, there are no public monuments, no statues, nor street names honoring his contribution. The street that did bear his name in the Hammond Addition was later renamed Gerald, after one of C. P. Higgin's children. The only reminder can be seen underfoot stamped into the concrete of older sidewalks along the street that became known as "Millionaire's Row" because of its magnificent mansions, many of which were built by Hammond's Missoula Mercantile and First National Bank associates.