The Grange. By 1872 it was largest mass organization in US history, organized farmers in many rural districts of MW, West & South as a political bloc hostile to Republican policies of monopoly & federal reconstruction. https://twitter.com/arielronid/status/1349432619839205385
In MN, Ignatius Donnelly, former Radical Rep, turned from Reconstruction to "reconstructing railroads." Broke w/ GOP for alliance w/ Greeley in 1872 & led section of Republican farmers out of the GOP & to Dems in 1873 & 74. Similar in Grange strongholds in OH, IL, IN, PA, etc.
Grange saw Reconstruction as discrimination vs southern planters & violating farmers' claims to equality. It was part of their nationalist vision of reconciliation. This was its founding principle from 1867 onwards.
At national level, Grange split on tariffs but many opposed Lib Reps protectionism. The one tax issue they fought for directly was repayment of post-CW cotton tax, a form of reparations to be paid to the white planter class.
This is the twitter version. But white farmer-labor democracy played bigger role in Reconstruction politics 1872-1874 than widely understood. Full version in my book: https://us.macmillan.com/books/9781429946926