US Army, WWII:
Armored Divisions: 16 total (1st through 14th, 16th and 20th)
Cavalry Divisions: 2 total (1st and 2nd)
Other Divisions: 73 total (5 Airborne, 67 Infantry, 1 Mountain)
1st through 9th Infantry
10th Mountain
11th Airborne
12th Infantry / Philippine Division (surrendered at Bataan, reconstituted 1944)
13th Airborne
--- no 14th, 15th, 16th ---
17th Airborne
--- no 18th, 19th, 20th,21st,22nd ---
23rd Infantry / Americal Division
24th through 45th Infantry
--- no 46th through 62nd ---
63rd Infantry
--- no 64th ---
65th, 66th Infantry
--- no 67th, 68th ---
69th through 71st Infantry
--- no 72nd, 73rd, 74th ---
75th through 81st Infantry
82nd Airborne
83rd through 97th Infantry
--- no 98th ---
99th and 100th Infantry
101st Airborne
102nd, 103rd, 104th Infantry
--- no 105th ---
106th Infantry
Total 91 Divisions (5 Airborne, 16 Armored, 2 Cavalry, 67 Infantry, 1 Mountain)
US Marines, WWII: 6 total (1st through 6th, each a bit larger than an Army Infantry division)
Tim