Honorable Mentions: 1903 Alternate
Where it all started, 1903. The first official World Series was played the same year the Cubs began their identity as the "Cubs". Although this was the beginning of one of the league's most historic franchises, the uniforms wouldn't have told you so.
The standard "fold-down" collar with a pocket on the left breast was all white besides a blue "C" adorned on the pocket. This was the alternate. There is nothing spectacular about this uniform other than it came in the infancy of Cubs history and provided a representation of what the Cubs have called home for well over a century.
Honorable Mentions: 1906 Road
This kit was included in the honorable mentions list due to the closely aligned color scheme of the Cubs' lifelong rival, the Chicago White Sox. On top of the normalized collared tops, the jersey and pants were gray with a black cap, belt, and socks.
When you see this uniform, think West Side Park and the Cubs losing in the World Series to their crosstown counterparts Chicago White Sox. Frank Chance was in the infancy of his Cubs' managerial career and led Chicago to 116 wins, a record which still stands today. The pitching staff has a team ERA of 1.76 while the offense scored the most runs in the league. Was the success due to a change in threads? We won't know for sure, but these uniforms are certainly embedded in Cubs history.