CACA = Central America Collective Army
CCA = Caribbean Collective Army


basically before USA entered WW2 in 1945 they put a lot of time, money & resources into modernising and developing Central America & Caribbean because they:

• provide vital sea canals connecting Atlantic & Pacific oceans.
  
• provide vital seaports & harbours for Allied ships.
  
• provide plenty of natural resources.
  
• provide first-line-defence of USA's southern flank to stop enemies invading USA from south.

as the Axis expanded greatly throughout the war it became obvious Central America & Caribbean are under threat. USA created the following Armies to unify command of forces in the region:

• CACA (Central American Collective Army): Panama, Nicaragua, Mexico, Honduras, Costa Rica, Guatemala, El Salvador
  
• CCA (Caribbean Collective Army): Dominican Republic, Cuba, Haiti