During the Mexican-American War, the army grew from a permanent standing force of 8,000 to almost 100,00 men (30k soldiers, 60+k milita). In the post-war period, the army has drawn down to about 20 thousand troops with only a few thousand soldiers west of the Mississippi.

As part of a major reorganization, in October 1853 the ten divisions (6 western, 4 eastern) were consolidated into five departments – East, West (Kansas, Nebraska, and Utah Territories), Texas, New Mexico, and Pacific (California & Oregon territory). The western commands are reorganized again in 1858, and return to six departments that look eerily similar to the pre-1853 organizational structure.

• D.California – Newman Clarke
• D.New Mexico – Benjamin Bonneville
• D.Oregon – W.S. Harney
• D.Texas – David Twiggs
• D.Utah – Albert Sidney Johnson
• D.West – Persifor Smith

All territory east of the Mississippi continues to be organized under a single “Department of the East”.

The officer corps

Officers are typically brevetted into their rank by their commander, but many will never be confirmed by Congress. As such it is common to find someone with a permanent rank of Lieutenant or Captain commanding a brigade with an acting title of Lt Colonel.

General ranks are limited to department heads and a few specialized commands reporting direct to either the Secretary of War or Winfield Scott. There are two levels – Brigadier (1-star) and Major General (2-star) – with Winfield Scott as the first 3-star Lieutenant General since George Washington.

There is no retirement age, so senior officers in the U.S. Army were born in the 18th century and most served in the War of 1812. But combat is the crucible – any officer with career aspirations served in the Mexican War, and younger, ambitious recruits have actively sought out service in the west supporting garrison duty, Indian campaigns and the various insurrections and uprisings (Bloody Kansas, Utah War, et al).

Selected commander bios

John B Floyd – Secretary of War under president Buchanan. Farmer and lawyer, former governor of Virginia. Considered a purely political appointment with marginal administrative skills.

Winfield Scott – Commanding General of the United States. Promoted to Lt Gen (3-star) in 1855, retroactive to 1847 for his leadership in the Mexican War. Called “Grand Old Man of the Army” and “Old Fluff and Feathers” for his love of traditional discipline. Ran for president as the Whig candidate in 1852. Virginian but not generally seen as a southern sympathizer.

John Wool – Promoted to Maj Gen (2-star) for service in the Mexican War. #2 ranking officer in the service. Formerly commander of the D.Pacific and currently commanding officer D.East.

Newman Clarke – Commander of the first brigade to step ashore at Veracruz. Commander of D.Pacific (all forces west of the Rockies) … and will be D.California after the reorganization.

David Twiggs – Promoted to 1-star in 1846 and served under Scott’s Expedition. Military governor during the occupation of Mexico. Currently commanding officer of D.Texas.

Persifor Smith – Brevetted to Major Gen. Military governor of Mexico City after the war, former commander Pacific Division, founded Fort Davis (El Paso), currently commanding D.West at Fort Leavenworth, and embroiled in “Bloody Kansas” (esp protecting the Lecompton congress)

Other notables

Col. Richard Delafield – Commandant of West Point, former commander of Corps of Engineers, head of Delafield Commission (US observers to the Crimean War).

Col Joseph Eggleston Johnston – Chief of Staff under Scott.

Col. William Loring – extensive campaigns in Oregon and against the western indians, on leave to Europe to study the Crimean War and emerging European tactics.

Col George Wright – Commander Ft. Dalles (major installation on the Columbia River) with extensive service in Oregon and Washington.

Col. Charles Ferguson Smith – Lead the Red River campaign (Minnesota). Now serving as #2 officer in D.Utah under Johnson.

Col. Edwin Vose Sumner – Commander Ft Leavenworth, 1st Cavalry. #2 officer in D.West under Smith

Lt. Col. Benjamin Beall – Commander 1st Dragoons and #2 officer in D.California under Clarke.

Col. William Harney – Senior cavalry officer at Veracruz, former commander of D.Texas. Recalled from leave in 1855 to lead punitive expedition against the Sioux in the Nebraska Territory – followed by other suppression activities against the Plains Indians. Rumored to be wintering over in Utah awaiting next assignment.

Capt George Pickett – Hero of the Battle of Chapultepec, served in D.Texas after the war. Currently commanding officer Fort Bellingham, Washington Territory.

Permanent posts in California

San Francisco & Northern Coast

• Fort Point, San Francisco, 1853
• Fort Mason (Post at Point San José), San Francisco, 1853
• Fort Alcatraz, San Francisco, 1853
• Fort Bragg, Mendocino County, 1857
• Fort Ter-Waw, Klamath River, 1857

Bay Area garrisons

• Benicia Arsenal, Benicia, 1851
• Benicia Barracks, Benicia, 1852

Central Valley & Gold Country

• Roop’s Fort, Fort Defiance, Susanville 1853
• Fort Humboldt, Eureka, 1853
• Camp Hollenbush (Fort Crook), Fall River Valley, 1857

Southern Coast & New Mexico

• New San Diego Depot, San Diego, 1851
• Fort Yuma, 1851
• Camp Burton, near San Diego, 1855
• Fort Tejon, near Lebec, 1854

Under construction

• Fort Mojave
• Fort Gaston

Planned/Proposed
Fort Beale
Fort Piute
Fort Soda, Hancock’s Redoubt
Fort Soda Springs
Camp Cady
Camp Allen, Oakland
Camp Dragoon Bridge