Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N943AN - Boeing 737NG 823/W - American Airlines AAL1520/AA1520 (DFW-CHS-DFW) - 4.2 mi away @ 37000 ft, heading NE at 636 mph. Spotted 40x before! [01:27:20 PM CDT] #AD185A #N943AN #B738 #AMERICAN #AAL1520 #AA1520 #ADSB #ADSBbot