The full structure is below
ARMY: III Corps/4th Infantry Division/(1st Combat Brigade/3rd Styker Brigade) ,/1st Calvary Division/(2nd Air Assault Brigade/,5th Air Assault Brigade)
1st Infantry Division/(2nd Combat Brigade)(9th Air Assualt Brigade)
XVIII Corps/82nd Airborne Division/(4th Air Assault Brigade/2nd Combat Brigade/101st Airborne Division/(1st Air Assault Brigade/7th Aviation Brigade) /3rd Infantry Division/(25th Recon Combat Brigade/3rd Combat Brigade)173rd Airborne Division/(92nd Field Assualt Brigade)(5th Combat Brigade)
V Corps/25th Infantry/(4th Fire Brigade/7th Signal Brigade)/1st Armored(3rd Armored Brigade/7th Heavy Armored Brigade)
Like the marines, the army operates primarily as a ground force, utilizing armor, humvees, and soldiers to achieve it's objectives. It is less maritime however, and generally does not deploy in an amphibious assault role.
[If anyone has a problem with what I have written here so far, change it, remove it; whatever. I am only an E4, so if a superior wants to create the army's wiki page, by all means, do so]