The US spritepack adds 17 more US sprites in the game. You will se among other things, the Iowa Class battleship, the B-29 Super Fortress and the M4/E8 Sherman Medium Tank.
8 new ships:

• BB: Iowa Class
  
• CV: Essex Class
  
• BB: North Carolina Class
  
• CV: Lexington class
  
• SS: Gato Class Submarine
  
• CL: Brooklyn Class
  
• CA: Baltimore Class
  

• DD: Fletcher Class
  4 new airplanes:

• Interceptor: North American F-86 Sabre

• Strategic Bomber: B-29 Super Fortress

• Interceptor: Grumman F6F Hellcat

• Tactical Bomber: Martin B-26 Marauder
  4 new tanks:

• Light Amour: M-5 Stuart

• Medium Armour M-3 Lee

• Medium Armour: M4/E8 Sherman

• Heavy Armour: M-26 Pershing