The Chicago Marathon began in 1977 and steadily grew into one of the defining races of the modern marathon era. Over nearly five decades, the event has helped shape the global marathon boom by attracting the world’s greatest athletes and serving as the stage for numerous historic performances. Chicago has witnessed multiple world records, including Kelvin Kiptum’s legendary 2:00:35 performance in 2023 and Ruth Chepng’etich’s groundbreaking women’s world record of 2:09:56 in 2024. As a founding member of the World Marathon Majors and one of the most internationally recognized road races, the Chicago Marathon has become synonymous with speed, excellence, and the pursuit of marathon greatness.