The Supreme Court scheduled its review of the case for its Spring 1887 term, and the attorneys for both sides assembled their printed briefs. On view here is the title page of the state's brief on the facts, filed by State's Attorney Julius Grinnell, who had prosecuted the anarchists in the Criminal Court, and Illinois Attorney General George Hunt. They were assisted by the same three lawyers who worked with Grinnell during the trial. Defense attorney Black, still working with Moses Salomon and Sigmund Zeisler, filed the brief for his eight clients. Since the State of Illinois was now defending its handling of the case, they became the "Defendants in Error," and the defense during the trial became the plaintiffs.

The attorneys made the oral presentations of their arguments in front of six of the seven justices of the Illinois Supreme Court (Chief Justice John M. Scott was ill) for three days in mid-March. The court heard these pleas in session in Ottawa, Illinois, about eighty-five miles southwest of Chicago along the Illinois River. The oral arguments presented at that time by William Black and Leonard Swett are included in the "From the Archive" section of this Act.

In making the case for the state in the Brief on the Facts, Grinnell and Hunt began by summarizing what they called the history of the crime and the plaintiffs' connection to it. They said that they were "convinced that when all of the facts of the case are considered together there can be no question of the correctness of the rulings and the soundness of the distinguished judge who resided at the trial."

They asserted that a large conspiracy, "having for its object the destruction of the legal authorities of the state and county, the overthrow of the law itself, and a complete revolution of the existing order of society," had existed for several years; the bomb was thrown by one of its members "in pursuance of the objects of the conspiracy"; convincing evidence directly connected at least some of the convicted men to the bomb-throwing; some of them had for a long time advised the destruction of the police and other legally constituted authority; and, above all, each of the plaintiffs was an active member of the conspiracy, and hence responsible for the crime.

To the fact that bomb-thrower was not positively identified, the state had an answer ready: "If the person who actually threw the bomb was incited or encouraged to do it by reason of the speeches or articles referred to, then the authors of those speeches and articles are, under our statute in regard to accessories, equally guilty with the man who actually threw the bomb." And there was ample reason, Grinnell and Hunt maintained, to believe that the anarchists at the very least instigated the bomb-thrower, whoever he might be. "Our position upon this branch of the case," they stated, "is that the evidence shows overwhelmingly, when all taken together, that whoever threw the bomb was so instigated." The rest of the brief consisted of a compendium of the evidence for the conspiracy (including all the writings, speeches, and political activities of the defendants in the trial), followed by a reassertion of the state's version of what happened in the Haymarket.

Grinnell and Hunt filed a separate "Brief on the Law for Defendants in Error," in which they tried to bolster, by citation of numerous cases, their view on the laws of conspiracy, evidence, and accessories, as well as the judge's instructions to the jury, the complaints about the composition of the jury, and several other matters. The view they forwarded of conspiracy was especially aggressive, holding the defendants responsible even if the bombing was only the "natural result" of the conspiracy, not part of a specific plan. Both sets of lawyers cited some cases whose connection to the matter at hand was slender, and they naturally read all the cases they cited in a way that was most favorable to their own arguments.