Warrant Officers 

Pay Grade Rank Insignia Description
O-1 SECOND LIEUTENANT (2LT) Typically the entry-level rank for most Commissioned Officers. Leads platoon-size elements consisting of the platoon SGT and two or more squads (16 to 44 Soldiers).
  First Lieutenant insignia A seasoned lieutenant with 18 to 24 months service. Leads more specialized weapons platoons and indirect fire computation centers. As a senior Lieutenant, they are often selected to be the Executive Officer of a company-sized unit (110 to 140 personnel).
  Captain insignia Commands and controls company-sized units (62 to 190 Soldiers), together with a principal NCO assistant. Instructs skills at service schools and combat training centers and is often a Staff Officer at the battalion level.
  Major insignia Serves as primary Staff Officer for brigade and task force command regarding personnel, logistical and operational missions.
  Lieutenant Colonel insignia Typically commands battalion-sized units (300 to 1,000 Soldiers), with a CSM as principal NCO assistant. May also be selected for brigade and task force Executive Officer.
  Colonel insignia Typically commands brigade-sized units (3,000 to 5,000 Soldiers), with a CSM as principal NCO assistant. Also found as the chief of divisional-level staff agencies.
  Brigadier General insignia Serves as Deputy Commander to the commanding general for Army divisions. Assists in overseeing the staff's planning and coordination of a mission.
  Major General insignia Typically commands division-sized units (10,000 to 15,000 Soldiers).
  Lieutenant General insignia Typically commands corps-sized units (20,000 to 45,000 Soldiers).
  General insignia The senior level of Commissioned Officer typically has over 30 years of experience and service. Commands all operations that fall within their geographical area. The Chief of Staff of the Army is a four-star General.
  General of the Army insignia This is only used in time of War where the Commanding Officer must be equal or of higher rank than those commanding armies from other nations. The last officers to hold this rank served during and immediately following WWII.

The highest Army rank, known as General of the Armies, is traditionally considered the equivalent of a six star general. No insignia has ever been authorized for the rank, and it has only been held by two people in history: John J. Pershing and George Washington (posthumously).

The structure of U.S. ranks has its roots in British military traditions. At the start of the American War of Independence, uniforms, let alone insignia, were barely affordable and recognition of ranks in the field was problematic. To solve this, Gen. George Washington wrote:

"As the Continental Army has unfortunately no uniforms, and consequently many inconveniences must arise from not being able to distinguish the commissioned officers from the privates, it is desired that some badge of distinction be immediately provided; for instance that the field officers may have red or pink colored cockades in their hats, the captains yellow or buff, and the subalterns green."

From 1780, regulations prescribed two stars for major generals and one star for brigadier generals worn on shoulder boards, or epaulettes.

The period of 1821 to 1832 witnessed a brief period of using chevrons to identify officer grades, a practice that is still observed at West Point for cadet officers.

Colonels received their eagle in 1832, and four years later lieutenant colonels were using oak leaves and captains and first lieutenants their respective double and single bars. Both majors and second lieutenants had no specific insignia. A major would have been recognizable as he would have worn the more elaborate epaulette fringes of a senior field officer but without insignia. The color of insignia was gold on silver epaulettes in the infantry and vice versa in the other branches until 1851 when insignia became universally silver on gold for senior officers and gold for the bars of captains and first lieutenants.

From 1872 the majors received oak leaves in gold to distinguish them from the silver of lieutenant colonels and the bars of both captains and lieutenants became silver. In a similar fashion, 1917 saw the introduction of a single gold bar for second lieutenants. These changes created the curious situation (in terms of heraldic tradition) of silver outranking gold. One after-the-fact explanation suggested by some NCOs is that the more-malleable gold suggests that the bearer is being "molded" for his or her responsibilities -- as a field officer (second lieutenant) or staff officer (major). However, this explanation may be more clever than correct, for while the insignia for second lieutenant and major are gold colored they are actually made of brass, and brass is a base metal while silver is a precious metal. The rank order thus does not actually conflict with heraldic tradition.

The Civil War saw the development of distinctive rank insignia in the Confederate armies. Junior officers up to captain had a less elaborate pattern of braid on their tunic cuffs and wore collar insignia of three horizontal bars for a captain, two for a first lieutenant and one for a second lieutenant. Majors, lieutenant colonels, and colonels wore respectively one, two, and three stars on the collar, and all grades of general had the insignia of three stars (the middle being slightly larger) in an open top wreath pattern.