This feud started when a smaller newspaper, The Mantorville Express of Mantorville, Minnesota, published an editorial in which John E. Bancroft, the editor, defended paying for advertising in larger newspapers. Bancroft wrote that The Mantorville Express had contacted the Chicago Daily Press and Tribune to purchase advertising space and were rebuffed when Joseph Medill, the co-owner and managing editor of the Chicago Daily Press and Tribune, wrote back on December 23, 1858, stating “Dear Sir: We have no advertising to offer you that would be of any value to us. To publish our prospectus, would do very little good, as people in your State, subscribe chiefly for the New York Tribune-Which elected Douglas, and the N. Y. Ledger, which employs “Cobb” in its columns.”

This letter touched off a heated rivalry between the two major papers of the New-York Tribune and the Chicago Daily Press and Tribune, starting on January 29, 1859, when the New-York Tribune published the letter that was published in The Mantorville Express, along with an editorial denying the accusation of helping Douglas win the Senate election against Lincoln. “Now, it certainly is true” the editorial admitted, “ that the people of Minnesota are extensively addicted to taking and reading THE NEW-YORK TRIBUNE; and it may be that they have a like penchant for The New York Ledger, though we have no precise knowledge on that head. It is also true that The Ledger ‘employs Cobb;’ but how it is made out that THE N. Y. TRIBUNE ‘elected Douglas,’ we do not so clearly perceive.” This article went on to claim that the New-York Tribune supported Lincoln in his campaign against Douglas, although not as strongly as the Chicago Daily Press and Tribune, and that whoever lost this election would hold a stronger future than the winner, as they would be a martyr for their preferred cause with the freedom to run for a future office. In the case of the Senate election of 1858, this was Lincoln, and the New-York Tribune stated the belief that he would have a stronger political future because he lost than he would have if he had won.

On February 2, 1859, TheChicago Daily Press and Tribune responded to the New-York Tribune’s editorial, accusing the paper of “...the criminal folly of ...still clinging to the coat tails of ” of Douglas. Its stance regarding the New-York Tribune’s friendly attitude toward Douglas, the Chicago Daily Press and Tribune argued, had remained unchanged in previous months, that it “...repeatedly charged the New York Tribune, both before and after our election, with aiding and abetting Mr. Douglas, and damaging the Republican nominees and the Republican cause.”

This response mentioned a letter written by Greeley to William Herndon, Lincoln’s law partner, alluding to Greeley meeting with Douglas as the latter looked for support in his campaign for reelection to the U.S. Senate. In the aftermath of Douglas’s split with President James Buchanan over the Lecompton Constitution, Greeley and other Eastern Republicans were excited to have Douglas as an ally in their fight against the Buchanan administration and the expansion of slavery, and Greeley, via his editorial pages, urged voters in Illinois to support Douglas and other local anti-Lecompton Democratic candidates. “We wish to know then why the principal editor of the Tribune wrote letters to Mr. Lincoln’s law-partner last summer,” the Chicago Daily Press and Tribune asked, “telling the Republicans of Illinois to ‘nominate and elect their own man and he (Mr. Greely) would be entirely satisfied’? We refer to the letter ending ‘Do not consider ‘us all natural fools down this way’ -a very apt deprecation as we thought then.” “Whether Mr. Greeley allowed himself to be privately caucussed at Washington by our Senator or not,” the Chicago Daily Press and Tribune continued, “it is certain that the course which he immediately adopted, in writing to Mr. Herndon and so forth, would have been very appropriate in one who had had a half hour’s session with Douglas.” The paper further charged Greeley with supporting Douglas and abandoning Republicans by listing Douglas among the potential presidential candidates in 1860.

Ten days later, Greeley and the New-York Tribune published both the Chicago Daily Press and Tribune’s February 2 article and a response. Greeley defended the listing of Douglas as a potential 1860 presidential candidate as an act of political neutrality. Addressing the “Herndon letter,” Greeley claimed that hitherto he was unaware of Herndon’s partnership with Lincoln. He further claimed that Herndon had arrived at his office ten months previously on his way home from Washington, DC, volunteering “the assurance that he agreed with us perfectly with regard to Senator Douglas, and deplored the blind perverseness of Illinois Republicans who insisted on fighting him.” Greeley insisted that Herndon then went home to Springfield, Illinois, “and soon wrote us in an exact opposite key from that of his recent conversation.” If Herndon was party to the use of his correspondence with Greeley, Greeley requested that Herndon “publish them entire—not one, but all we ever wrote him with reference to the late Senatorial contest in Illinois-and let the public judge whether we ever led him to believe anything contrary to our public attitude and avowals.”

The Chicago Daily Press and Tribune responded to Greeley’s rebuttal on February 16, once again mentioning the letter written by Greeley to Herndon and stating that, although it did not have possession of the letter, its contents showed that Greeley seemed to be a supporter of the Illinois Republicans. This led to a feeling of betrayal by the writers of the Chicago Daily Press and Tribune when they saw that the New-York Tribune was listing Douglas as a top-level contender for the 1860 presidential race. The New-York Tribune provided an explanation of Greeley’s letters to Herndon, stating that Herndon met with New-York Tribune staff in 1858 and seemed to be in agreement on their levels of support for the Republicans in Illinois, and that Herndon must have misunderstood the level that the New-York Tribune would be willing to reject Douglas and the Democrats. The New-York Tribune explained the letter to Herndon showing support for the Illinois Republicans was consistent with their stance the entire time and any confusion was brought about by the conversation in New York between Herndon and Tribune staff in which both parties held differing stances while assuming they held the same. On March 8, the Chicago Daily Press and Tribuneblamed the New-York Tribune for the misunderstanding, as Herndon’s anti-Douglas views were well known to any that knew Herndon.

This dispute seems to have ended with the March 8 statement as no further statement from the New-York Tribune has been found.