The Nonpartisan League (NPL) was a political organization founded in 1915 in the United States by Arthur C. Townley, former organizer for the Socialist Party of America. On behalf of small farmers and merchants, the Nonpartisan League advocated state control of mills, grain elevators, banks and other farm-related industries in order to reduce the power of corporate political interests from Minneapolis, Minnesota and Chicago. 
The NPL goat served as the US League's mascot. It was known as "The Goat that Can't be Got." 
The League developed beginning in 1915, a time when small farmers in North Dakota felt exploited by out-of-state companies. One author later described the wheat-growing state as "really a tributary province of Minneapolis-St. Paul". Minnesota banks made its loans, Minnesota millers handled its grain, and Alexander McKenzie, North Dakota's political boss, lived in St. Paul.  Rumors spread at an American Society of Equity meeting in Bismarck that a state legislator named Treadwell Twichell had told a group of farmers to "go home and slop the hogs." Twichell later said that his statement was misinterpreted. He had been instrumental in previous legislative reforms to rescue the state from boss rule by MacKenzie and the Northern Pacific Railroad around the start of the 20th century.
Arthur C. Townley, a former flax farmer  from Beach, North Dakota, and former organizer for the Socialist Party of America, had attended the Society of Equity meeting. Afterward Townley and a friend, Frank B. Wood, drew up a radical political platform at Wood's kitchen table that addressed many of the farmers' concerns. Soon, Townley was traveling the state in a borrowed Model T Ford signing up NPL members for a payment of $6 in dues. Farmers were receptive to Townley's ideas and joined in droves.[ citation needed]
Proposing that the state of North Dakota create its own bank, warehouses, and factories,  the League, supported by a populist groundswell, ran its slate as Republican candidates in the 1916 elections. It won control of the state legislature and elected a farmer, Lynn Frazier, as governor with 79% of the vote. It also elected John Miller Baer to the United States House of Representatives. After the 1918 elections, in which the NPL won control of both houses of the legislature, the League enacted a significant portion of its platform. It established state-run agricultural enterprises such as the North Dakota Mill and Elevator, the Bank of North Dakota, and a state-owned railroad. The legislature passed a graduated state income tax, distinguishing between earned and unearned income; authorized a state hail insurance fund, and established a workmen's compensation fund that assessed employers. The NPL also set up a Home Building Association, to aid people in financing and building houses.
During World War I, Townley demanded the "conscription of wealth", blaming "big-bellied, red-necked plutocrats" for the war. He and fellow leader William Lemke received support for the League from isolationist German Americans.  The NPL's initial success was short-lived. A drop in commodity prices at the close of the war, together with a drought, caused an agricultural depression.
As a result, the new state-owned industries ran into financial trouble, and the private banking industry, smarting from the loss of its influence in Bismarck, rebuffed the NPL when it tried to raise money through state-issued bonds. The industry said that the state bank and elevator were "theoretical experiments" that might easily fail. Moreover, the NPL's lack of governing experience led to perceived infighting and corruption. Newspapers and business groups portrayed the NPL as inept and disastrous for the state's future.
In 1918, opponents of the NPL formed the Independent Voters Association. In 1921, the IVA was able to organize a special election to recall Frazier. Due to an ongoing agricultural depression and infighting within the NPL, Frazier was removed from office. He lost the recall election by a margin of 1.8% of the vote. He was the first U.S. state governor to be recalled. However, a year later he was elected to the United States Senate for North Dakota and served until 1940.
The decade of the 1920s was economically difficult for farmers, and the NPL's popularity receded. But the populist undercurrent that fueled its meteoric growth revived with the coming of the Great Depression and the Dust Bowl conditions of the 1930s. The NPL's William "Wild Bill" Langer was elected to the governorship in 1932 and 1936 (the two two-year terms separated by his declaration of North Dakota's secession from the United States in 1934, and his serving a jail term). After serving as governor, Langer was elected to the U.S. Senate, serving from 1940 until his death in 1959.
North Dakota Mill and Elevator and the Bank of North Dakota continue to operate today. The legislature in 1932 prohibited corporate farming and corporate ownership of farmland.
In the 1916-1919, a different Non-Partisan League operated in Alberta, Canada.  Among its candidates was former governor of Kansas John W. Leedy, who had moved to Canada and became a citizen. He ran as a candidate for the Alberta NPL in the 1917 Alberta provincial and federal elections, but was not elected.
In the Saskatchewan general election of 1917, there were seven candidates who stood for election as Non-Partisan League candidates. They garnered 4,440 votes (2.36% of the popular vote), but did not elect a candidate. 
In 1926, Yasaburo Shimonaka organized Nohmin-Jichikai (農民自治会, Peasant Self-Government Association) with Teisuke Shibuya, Inosuke Nakanishi and Sanshiro Ishikawa in Tokyo. This Association aimed to launch Japanese NPL. But there is no connection between NPL in US and Japan, and Nohmin-Jichikai failed to spread the movement in Japan and ended in 1928. 
- Northern Lights (1978), a feature film starring Joe Spano, portrayed early 20th century conditions in North Dakota and the rise of the NPL among immigrant farmers. The film won the 1980 Camera d'Or award for best first film at the Cannes Film Festival.
- The NPL arose as a faction within the Republican Party in 1915. By the 1950s, its members felt more affiliation with the Democratic Party and merged with that party of North Dakota. The North Dakota branch of the Democratic Party is therefore known as the North Dakota Democratic-Nonpartisan League Party to this day. The Executive Committee of the NPL still formally exists within the party structure of the North Dakota Democratic-NPL. It is headed by former State Senator S. F. "Buckshot" Hoffner (D-NPL, Esmond), Chairman, and former Lt. Governor Lloyd B. Omdahl, Secretary.
- The Nonpartisan League laid a foundation of enriched public ownership and responsibility in such institutions as a state bank. One study has drawn conclusions that publicly operated institutions such as the state bank have helped North Dakota weather these economic storms. 
- The Bank of North Dakota was created to address market failures associated with monopoly power among large financial and business institutions in the early twentieth century. This market power meant that small farming operations had inadequate access to credit. One of the goals of the Nonpartisan League was to remedy limited access to credit by establishing this institution. A measure of the public good brought about by the Bank's establishment that still stands today is what some have identified as the Bank's role in reducing the impact of economic recession. The public-private relationship establishes roles assigned according to what each sector does best, allowing the mutual benefit of public and private banks balancing out inequality and building equality, thus creating an economic safety net for North Dakota citizens. These early roots of the Democratic-Nonpartisan League party have been celebrated for establishing a foundation that rights the state in times of national crisis and provides economic security to generations of the state's farmers.
- The Fred and Gladys Grady House and the Oliver and Gertrude Lundquist House, both in Bismarck, North Dakota, are listed on the U.S. National Register of Historic Places as examples of the work of the Nonpartisan League's Home Building Association. 
- Agricultural Workers Organization
- Granger movement
- Bolt Weevils
- Minnesota Farmer-Labor Party
- Minnesota Democratic-Farmer-Labor Party
- Socialist Party of North Dakota
- North Dakota Democratic-NPL Party
- Goldstein, Robert Justin (2001). Political Repression in Modern America. University of Illinois Press. p. 99. ISBN 0-252-06964-1.
- Vogel, Robert (2004). Unequal Contest: Bill Langer and His Political Enemies. Crain Grosinger Publishing. p. 2. ISBN 0-9720054-3-9.
- Lubell, Samuel (1956). The Future of American Politics (2nd ed.). Anchor Press. pp. 145–147.
- Anthony Mardiros (1979). William Irvine: The Life of a Prairie Radical. p. 56.
- Elections Saskatchewan - Election Results - 1917.
- Kodrzycki, Yolanda K; Elmatad, Tal (May 2011). The Bank of North Dakota: A model for Massachusetts and other states? (PDF) (Report). New England Public Policy Center. Retrieved December 6, 2011.
- Michelle L. Dennis (February 2006). "National Register of Historic Places Multiple Property Documentation: Nonpartisan League's Home Building Association Resources in North Dakota" (PDF).
- Ellsworth, Scott. Origins of the Nonpartisan League. PhD dissertation. Duke University, 1982.
- Gaston, Herbert E. The Nonpartisan League. New York: Harcourt, Brace and Howe, 1920.
- Huntington, Samuel P. "The Election Tactics of the Nonpartisan League, Mississippi Valley Historical Review, vol. 36, no. 4 (March 1950), pp. 613-632. in JSTOR
- Lansing, Michael. Insurgent democracy: the Nonpartisan League in North American politics (University of Chicago Press, 2015)
- Lipset, Seymour M. (1971) Agrarian Socialism, (University of California Press, Berkeley)
- Morlan, Robert L. Political Prairie Fire: The Nonpartisan League 1915-1922. St. Paul: Minnesota Historical Society Press, 1955.
- Morlan, Robert L. "The Nonpartisan League and the Minnesota Campaign of 1918," Minnesota History, vol. 34, no. 6 (Summer 1955), pp. 221–232. In JSTOR
- Moum, Kathleen. "The Social Origins of the Nonpartisan League." North Dakota History 53 (Spring 1986): 18-22.
- Moum, Kathleen Diane. Harvest of Discontent: The Social Origins of the Nonpartisan League, 1880-1922. PhD Dissertation. University of California, Irvine, 1986.
- Nielsen, Kim E. "'We All Leaguers by Our House': Women, Suffrage, and Red-Baiting in the National Nonpartisan League." Journal of Women's History, vol. 6, no. 1 (1994), pp. 31–50.
- Reid, Bill G. "John Miller Baer: Nonpartisan League Cartoonist and Congressman," North Dakota History, vol. 44, no. 1 (1977), pp. 4–13.
- Remele, Larry. "Power to the People: The Nonpartisan League," in Thomas W. Howard, ed. The North Dakota Political Tradition. Ames, IA: Iowa State University Press, 1981.
- Remele, Larry R. "The Lost Years of A.C. Townley (after the Nonpartisan League)." ND Humanities Council Occasional Paper, (1988) no. 1, pages 1–27
- Rude, Leslie G. "The Rhetoric of Farmer‐Labor Agitators." Communication Studies 20.4 (1969): 280-285.
- Saloutos, Theodore. "The Expansion and Decline of the Nonpartisan League in the Western Middle West, 1917-1921," Agricultural History, vol. 20, no. 4 (Oct. 1946), pp. 235–252. In JSTOR
- Saloutos, Theodore. "The Rise of the Nonpartisan League in North Dakota, 1915-1917," Agricultural History, vol. 20, no. 1 (Jan. 1946), pp. 43–61. In JSTOR
- Schoeder, Lavern.Women in the Nonpartisan League in Adams and Hettinger Counties. (In "Women on the Move", edited by Pearl Andre, 47-50: Book produced for the International Women's Year for North Dakota Democratic-NPL Women, 1975).
- Starr, Karen. "Fighting for a Future: Farm Women of the Nonpartisan League," Minnesota History, (Summer 1983), pp. 255–262.
- Vivian, James F. "The Last Round-Up: Theodore Roosevelt Confronts the Nonpartisan League, October 1918," Montana: The Magazine of Western History, vol. 36, no. 1 (Winter 1986), pp. 36–49. in JSTOR
- Wasson, Stanley Philip. The Nonpartisan League in Minnesota: 1916-1924. (PhD Dissertation, University of Pennsylvania, 1955).
- Wilkins, Robert P. "The Nonpartisan League and Upper Midwest Isolationism, Agricultural History, vol. 39, no. 2 (April 1965), pp. 102–109. In JSTOR
- Nonpartisan League in MNopedia, the Minnesota Encyclopedia
- North Dakota Democratic-NPL Party Website
- North Dakota State University Institute for Regional Studies Nonpartisan League Collection
- Article on the NPL from the Progressive Populist
- Northern Lights - docudrama of the forming of the Nonpartisan League in North Dakota*
- Socialist Herald / The Herald (1915-1916) Seattle newspaper associated with the NPL.