Nickolas Kessler was born in Befort, Canton Echternach, in the Grand Duchy of Luxembourg, on May 26, 1833, the son of Nickolas and Catherine Kessler. Kessler immigrated to the United States, arriving in New York on January 10, 1854. He lived in Ohio, Michigan, and Illinois, before traveling to Colorado in 1858 to search for gold.

In September 1863, Kessler followed the gold rush to Bannack, Montana Territory. In May 1865, he moved to Last Chance Gulch, the site of what is today Helena, where he purchased an interest in Charles Beehrer's fledgling brewery located on Ten Mile Creek. Beehrer founded Montana's first brewery, The Virginia Brewery of Virginia City, in 1863. Within a few months Kessler purchased his partner's interest and continued the brewery as sole proprietor, although he was briefly joined by brewer Ignace Miller in the 1870s. The brewery was known variously as Charles Beehrer and Co., Ten Mile Creek Brewery, Beehrer and Kessler, Ten Mile Brewery, Nick Kessler's Brewery, Kessler's Brewery, Kessler Brewery, Kessler's Brewery and Bottling Works, and Kessler Brewing Company.

In 1886 Nickolas Kessler directed the construction of an entirely new plant at the brewery, furnished with the first refrigeration machine in Montana and the first carbonic acid gas machine to be used in an American brewery. Kessler installed the first glass-lined storage tanks in the state in 1903, and in 1907 he installed the first bottling pipe line in the Rocky Mountain area.

Nickolas Kessler established a small brickyard at the brewery in the late 1860s or early 1870s. In May 1875, Kessler entered into a short-lived partnership with Matthew Wormer, a brickyard employee. Kessler bought the competing C.C. Thurston Brickyard (1885-1888), and made employee Charles H. Bray manager of both yards. Kessler and Bray mechanized the brickyard, vastly increasing production to meet the demands of a growing Helena. With the establishment of Fort Harrison in 1892-1893, the brickyard expanded to include a sewer tile press and the company incorporated as Kessler Brick and Sewer Pipe Works. The Kessler brickyard later consolidated with the Switzer Brick and Terra Cotta Company and incorporated under the name of The Western Clay Manufacturing Company, with Kessler and Jacob Switzer as the stockholders and Bray as secretary and general manager. The Kessler brickyard also secured the Switzer clay bank in Blossburg. Prior to purchasing the Switzer clay source, the Kessler yard obtained its clay from a bank on East Lawrence Street. Charles Bray acquired the Switzer and Kessler family stock in the 1920s, thereby becoming sole owner of the brickyard.

Nickolas Kessler also invested in real estate, rental property, and mining. He owned a saloon on Main Street in Helena, which served as his office for many years. The name of the Kessler saloon is unknown. He also ran a saloon in Marysville in partnership with Mike Tuohy, operated Kessler and Miller's Beer Hall and Saloon in partnership with Ignace Miller in Helena, and bought saloons in Boulder, Hassel, and elsewhere. Kessler also operated a farm and ranch, and ice pond to serve the needs of the brewery and brickyard.

Nickolas was a member of the Territorial Legislative Assembly in 1877, served as president of the Society of Montana Pioneers from 1897 to 1898, and was a member of the board of Kessler School in Helena. He died in Helena on December 11, 1901.

In 1873 Nickolas Kessler married Louisa Ebert, who was born June 15, 1849, in Williamsburg, New York, the daughter of G. Ebert, a German immigrant. The couple had three children: Charles N. (born July 9, 1874), Frederick E. (born in 1876), and Mathilda. Louisa died on December 18, 1880.

Charles N. Kessler, Nickolas's eldest son, began working at the brewery in 1891. He attended the Wahl-Henius Institute, a Chicago school pioneering in scientific brewing methods, and graduated in 1895. Following incorporation of the brewery in 1901, C.N. Kessler assumed the presidency of Kessler Brewing Company. In this capacity it fell to him to fight the prohibition movement, as well as growing competition from large eastern breweries made possible by bottled beer and developing interstate transportation networks. As an officer and founding member of the Montana State Brewers Association (organized in April 1902, as an associate member of the United States Brewers Association), Kessler actively opposed the growing prohibition movement and negotiated contracts with the International Union of the United Brewery Workmen. Kessler, a Republican, was elected senator to the Eleventh and Twelfth Sessions of the Montana Legislative Assembly (1909, 1911), where he opposed prohibition legislation. He was also a member of the anti-prohibition Montana Commercial and Labor League.

In 1916 Montanans voted for statewide prohibition which went into effect on January 1919. On June 28, 1919, the U.S. Collector of Internal Revenue certified the destruction of 588 gallons of Kessler beer, and the Kessler Brewery closed.

The brewery was re-incorporated in 1933, following the repeal of the Eighteenth Amendment. Frederick Kessler, who during the Prohibition years owned and operated the Placer Hotel in Helena, assumed the major role in financing the reestablishment of Kessler Brewery. Frederick was named president of the resuscitated brewery, and C.N. Kessler became vice president in charge of brewing operations. F.S. Jacobsen of Helena was a major stockholder. Frederick Kessler died in January 1949, and his son-in-law, Marc M. Buterbaugh succeeded him as president of the firm. Albert N. Berg became secretary. The brewery continued operation until July 1953. During its last year of operation the brewery, with a 40,000 barrel capacity, sold only 4,000 barrels. In 1984 a Kessler Brewery, owned by Montana Beverages, Ltd., began producing Kessler Beer. Montana Beverages, Ltd., while using the Kessler name, is not associated with the Kessler family.

During Prohibition C.N. Kessler investigated new business opportunities, including the Great Falls-based Nick Baatz Company, founded by early Great Falls bottler Nicholas Baatz. Baatz's firm had diversified into real estate, farming and ranching, soda and mineral water production, wholesale distribution of cigars and glassware, as well as becoming stockholder and distributor for Washington Liquid Gas Company.

Montana's first oil boom of the 1920s, sparked by oil discoveries at Elk Basin in Carbon County, followed by discoveries at Devil's Basin in Musselshell County, at Cat Creek in Petroleum County, and at the important Kevin-Sunburst Field in Toole County, attracted C.N. Kessler's attention. He investigated various oil firms and invested in some, notably the Golden Eagle Oil Company of Helena. Gordon Campbell, a principal in Montana's early oil industry and a developer of Devil's Basin and the Kevin-Sunburst field, kept Kessler informed of exploration efforts.

C.N. Kessler was an avid amateur historian of Montana and the Northwest. He built a substantial personal library and artifact collection of Montaniana which he maintained until his death. He was also interested in geology and mining and developed a collection of minerals, and related literature.

In 1905 C.N. Kessler married Sarah Hewett (1885-1941), daughter of Basin banker Marcus L. Hewett. They had two children C.N., Jr. (1907-1962), and Marietta (1912-1944). The Kesslers lived in Helena until 1923 when they moved to Los Angeles. They returned to Helena in 1933 to reopen the brewery, though they continued to maintain a home in Los Angeles. C.N. returned to California in the early 1950s and died in Los Angeles on October 25, 1957.

Frederick Kessler married Florence M. Gordon (1880-1955), daughter of John and Helen Kern Gordon of Whitewater, Wisconsin, on September 4, 1902. The couple had two daughters, Louise and Helen. Frederick Kessler died in 1949. Helen Kessler (1903-1973) married Marc W. Buterbaugh (1898-1973).

In 1904 Mathilda "Tillie" Kessler married William B. Cochran, a professional soldier stationed at Fort William Henry Harrison. The couple had three children: Louise, William, Jr., and Marion. The Cochrans retired to Princess Anne, Maryland.