Carter Harrison III Democratic John A. Roche Republican The Chicago mayoral election of 1887 saw Republican John A. Roche win by a landslide, receiving more than a two-thirds majority of the vote, defeating United Labor Party nominee Robert S. Nelson by more than 36 points (a margin of victory which was itself greater than Nelson's vote share), in a race where the Democratic Party had failed to field a candidate.

Incumbent Democratic mayor Carter Harrison III had opted to retire from the mayoralty instead of seeking re-election to a fifth term.

[8] The United Labor Party nominated Robert S. Nelson, who (in the absence of a Democratic nominee) was Roche's sole opponent in the election.

[8] Incumbent mayor Harrison, while formally not backing either candidate, dismissed many Democrats' worries about the prospect of a Nelson mayoralty, and also cautioned that a Roche election could spur the passage of additional blue laws.

"[10] Some prominent Chicagoans such as John M. Smyth spoke with the impression that Harrison outright supported Nelson's candidacy.

[11] Roche received a roughly 27,000-vote margin-of-victory, which at the time was the greatest number of votes that had ever separated a Chicago mayoral winner from an election's runner-up.