[2][5] In 1865, Godkin was asked by a group of abolitionists, led by landscape architect Frederick Law Olmsted, to found a new weekly political magazine.

[7] Under Godkin's leadership the Post[8] broke with the Republican Party in the presidential campaign of 1884, when Godkin's opposition to nominee James G. Blaine did much to create the so-called Mugwump party, and his organ became thoroughly independent, as was seen when it attacked the Venezuelan policy of President Grover Cleveland, who had, in so many ways, approximated the ideal of the Post and Nation.

His attacks on Tammany Hall were so frequent and so virulent that in 1894, he was sued for libel because of biographical sketches of certain leaders in that organization;[5] the cases never went to trial.

He supported the National Democratic Party (United States) third ticket because it championed a gold standard, limited government, and free trade.

[5] He was buried at Saint Michael's Church in Haselbech, Daventry District, Northamptonshire, England, near the home of the friend with whom he had been staying.

[11][12] Godkin shaped the lofty and independent policy of the Post and The Nation, which had a small but influential and intellectual class of readers.

However, he had none of the personal magnetism of Horace Greeley, for instance, and his superiority to the influence of popular feeling made Charles Dudley Warner describe The Nation as "the weekly judgment day".