The Mexican War

Mexican War, 1846-1848

• Texas wanted to be annexed.• U.S. government wanted New Mexico and

California.• Mexico did not want to:

– Recognize Texas independence or annexation,– Sell New Mexico and California

James K. Polk’sPlatform, 1844

• Annexation of Oregon• Annexation of Texas• Acquisition of New Mexico and California

United States, 1846

United States, 1846

“American blood has been shed on

American soil !

January: Polk orders occupation of disputed area.30 April, 1846: Mexican forces cross the Rio Grande.

U.S. Army vs. Mexican Army

U.S.• Professional

– Long-service soldiers (5 yrs)– Most junior officers: USMA

• Well-equipped• Well-led• Confident

– Ethnocentric– Racist

Mexico• Some professional

soldiers and some patriotic volunteers– Courageous, if well-led

• Political senior officers• Poorly trained• Poorly equipped• Poorly led• Little real sense of

Mexican nationalism

Operational Overview

1846• April - May:

Opns. along the Rio Grande• Sept. 20-24, 1846: Battle of

Monterey

1847

• 22-23, Feb Battle of Buena Vista

Doniphan Expedition:• Feb. 28, 1847: Battle of the

Sacramento, Northern Mexico.

• 18 Aug: Santa Fe occupied• 25 Sep: Kearny leaves for CA• 6 Dec: Battle of San Pasqual,

• Jan. 9, 1847: Battle of La Mesa (Los Angeles), Southern California.

• Dec. 1846 - Feb. 1847: Rebellion in New Mexico

Texas-Mexico Border New Mexico and California

Operational Overview

• 9-29 Mar: Siege of Vera Cruz • 18 Apr: Battle of Cerro Gordo • 19-20 Aug: Battles of Contreras and Churubusco • 8 Sep: Battle of El Molino del Rey • 13 Sep: Battle of Chapultepec • 13-15 Sep: Battles for Mexico City

• [ Sep. 14-Oct. 12: Siege of Puebla ]

1847 - Mexico City Campaign

Battle of Palo Alto

The Approach to Monterrey

After Monterrey . . .

• Texas physically secured.• New Mexico occupied.• California secured by January• Now what ?

Political considerations . . .

• Scott is a Whig with political aspirations.• Taylor has no party affiliation;

Assumption: Whig• The winning general will be the next President.• Polk wants a general who’s a Democrat.• Choice: Thomas Hart Benton, Senator from

MO

The strategic decision . . .

• An army will have to go into central Mexico.

• Scott will head that army.• The army will land at Vera Cruz.

The Operational Plan

Scott’s problem . . .

• Has to take Vera Cruz quickly.• Summer brings the “vomito”

Yellow Fever

Vera Cruz falls in 20 days.

On to Mexico City !

Cerro Gordo

“The Halls of Montezuma”

Scott’s occupation policies . . .• Paid for supplies.• Enforced the law - against his soldiers.• Recognized the Church.• Eventually made peace with Nicholas Trist.• Trist eventually made peace.

• Much of Scott’s glory lost in his squabble with Gideon Pillow.

Treaty of Guadalupe Hidalgo

• 2 Feb. 1848: Signed • 10 March: U.S. Senate ratifies• 25 May: Mexican government ratifies

• Texas annexation recognized wit Rio Grande as the border.

• New Mexico and California ceded for $15 million plus unpaid claims

The Cost

United States

1,177 KIA

3,669 WIA

11,155 Died of disease

16,001

Mexico

12,866 KIA

1,360 WIA

? Died of disease

??Estimated cost to U.S.: $97,500,000

Results . . .

• U.S. consolidates it continental position.• Question: Slaves in the territories ?• Mexico’s future linked to the U.S.• A mark on the Mexican soul.• Greater Mexican nationalism.

The objective was achieved at the least cost and in the most humane

way possible.

The means and the ends matched perfectly

A war of conquest . . .

• Poses an interesting moral question.• Was this a “just war” ?• Do you want to give the territory back ?

Legacy for the Army . . .

• Mexico teaches a generation of officers how to fight:– Fire a volley and then charge.– Well-led soldiers can take any position.

• Revolutionary War tactics and technology.• Success would blind many to the

technological innovations of the 1850’s.