Answer:
The group that was formed in 1891 in order to help poor farmers fight against big corporations was the Populist Party.
Step-by-step explanation:
The Populist Party was a populist agrarian political party of the United States of America that was active in the last decade of the 19th century and the first of the 20th. After its foundation in 1891, it became an important force in the southern and western states of the United States, representing the low and middle class farmers of these regions of the country, where it obtained representation in the legislative assemblies of some of them, although it never obtained a national representation. In that year it presented James B. Weaver as the candidate for the presidency, who obtained 8.5% of the votes. The party collapsed after the Democratic candidate William Jennings Bryan, with whom it had allied, failed to be elected in the presidential election of 1896. However, a party faction continued to operate in the first decade of the 20th century, although it never got the popularity of the party of the early 1890s.