This page captures ADS-B traffic data for Chicago O'Hare International Airport (ORD/KORD) on October 1, 2025, the 70th anniversary of the airport's opening to commercial aviation. Over the course of the single day, 2,226 flights were recorded across 858 unique aircraft, averaging 92.8 flights per hour. The split between arrivals and departures was close but not even: 1,164 arrivals versus 1,062 departures. Traffic ran continuously from 00:00 to 23:59 CDT, though the overnight hours were sparse, with fewer than 15 total movements in each of the first two hours. The 17:00 hour was the busiest of the day at 161 total flights, with 92 arrivals and 69 departures. Several other hours also crossed 150 movements, including 11:00 (156), 15:00 (157), and 18:00 (149). Approach and departure directions were broadly distributed, but east was the most common vector for both arrivals (165) and departures (162), followed by west and SSE. The top route by combined frequency was ORD-LGA, with 30 arrivals and 30 departures. DCA, DFW, DTW, DEN, and MSP each accounted for 31 combined movements. Toronto Pearson (YYZ) was the only non-U.S. airport in the top ten, with 30 total flights. Altitude data spans 1,591,938 ADS-B position points. The most frequently observed altitude band was 1,000-2,000 feet (139,508 points), followed by a secondary concentration between 35,000 and 38,000 feet, where the three busiest high-altitude bands each exceeded 55,000 points. The highest recorded altitude was 46,575 feet, logged by N60CK on a departure to Laconia Municipal Airport (LCI). The longest flight by distance was an arrival from Washington Dulles (IAD) covering 4,076.8 nautical miles over 818.6 minutes. Of the 858 unique aircraft, 774 were registered to the United States, with smaller counts from Canada (10), China (8), Japan (7), and 14 other countries.