Rotary began on the evening of 23 February 1905, when Harris met with three business colleagues in hopes of recapturing in a professional club the same friendly spirit they had experienced growing up in small-town America. They called their club the Rotary Club of Chicago, after the early practice of rotating weekly meetings among members' offices. As the Rotary movement grew and clubs were chartered around the world, Rotarians took up community service projects and promoted ethical standards in business.

Paul P. Harris (1868-1947) was a Chicago attorney in 1905 when he had an idea for a club in which professionals could share "mutual cooperation and informal friendship such as all of had once known in our villages." On the evening of Thursday, 23 February 1905, Harris gathered three business acquaintances to form a group that became the Rotary Club of Chicago, initiating the world's first service organization. Harris became the first president of what would later become Rotary International, the association of Rotary clubs around the world with 1.2 million members united under the motto Service Above Self.

Silvester Schiele (1870-1945) was a coal dealer and a client of Paul Harris in 1905. Born in rural Indiana, Schiele liked to tell Harris interesting anecdotes of his "young pioneer" boyhood. During the course of their business dealings, Harris first shared the idea with Schiele for a new kind of club for professionals. On 23 February 1905, Harris invited Schiele for dinner to develop his ideas of a fellowship and booster club. In addition to becoming first president of the Rotary Club of Chicago, Schiele developed a close lifelong friendship with Harris.

Gustavus H. "Gus" Loehr (1864-1918) was a Chicago mining engineer who lent his office on the seventh floor of the Unity Building at 127 Dearborn Street in Chicago for the first gathering of the founders of Rotary on 23 February 1905. Loehr invited Hiram Shorey to this meeting. His health later deteriorated and he left the club, but remained a supporter of Rotary until his death at age 53.

Hiram E. Shorey (1862-1944) was a merchant tailor in 1905. One of the founding four members of the Rotary Club of Chicago, he remained a Rotarian for only a short time before moving back to his home state of Maine. Upon his later return to Chicago, he rejoined for a brief time before resigning again. Despite his brief membership, Shorey was always supportive of the Rotary Club of Chicago and voiced pride at his early association with Rotary.