In terms of fatalities Bulge was second, Gettysburg fourth:
1 Battle of Meuse-Argonne World War I: 26,277
2 Battle of the Bulge (WW2) 19,276
3 Battle of Okinawa (WW2) 12,513
4 Battle of Gettysburg (Civil) 7,863
5 Battle of Guadalcanal (WW2) 7,099
6 Battle of Iwo Jima (WW2) 6,821
7 Antietam (Civil) 3,654
8 Battle of Shiloh (Civil) 3,482
9 Bull Run II (Civil) 3,000
10 Battle of Saipan (WW2) 2,949
Thanks for that correction...I thought G-burg was in the 50-60K range, and frankly hadn’t even thought the US suffered anything like that number of concentrated KIA in WWI at all.