Mexican War and Introduction to the Civil War

Lsn 4

Agenda• Mexican War

– Limited War– Turning Movement– Technology– Junior Officers

• Introduction to Civil War– Road to War– Causes– Objectives and Strategies– Comparison

Limited War: Winfield Scott

• Epitomized the professional officer– Served in War of

1812, brevetted to major general

– Studied European tactics

– Became general-in-chief in 1841

• Selected by President Polk to lead a second major campaign in Mexico (Zachary Taylor’s was the first)

Limited War: Objective• Objective as a principal of war

– When undertaking any mission, commanders should have a clear understanding of the expected outcome and its impact

– Commanders need to appreciate political ends and understand how the military conditions they achieve contribute to them.

• Winfield Scott saw Mexico as a war of limited objectives, to be waged by limited means

Limited War: Objective• Based on this belief, Scott developed a

largely political strategy • Believed that Mexican political life centered

around Mexico City so completely that capturing the capital would paralyze the country and oblige the Mexican government to sue for peace in order to remain a government at all

• Therefore his objective was to capture Mexico City, not to destroy the Mexican army

Limited War: Treatment of Civilians

• Scott conducted his campaign with strict regard for the rights of the Mexican citizens, making every effort to confine bloodshed and suffering to the Mexican army rather than the civilian population.

• He scrupulously regulated his soldiers’ conduct and interaction with Mexican civilians, reducing contact to the minimum necessary for the sustenance of his army and the morale of his troops.

Limited War: Treatment of Civilians

• “But, my dear Sir, our militia & volunteers, if a tenth of what is said to be true, have committed atrocities—horrors—in Mexico, sufficient to make Heaven weep, & every American, of Christian morals, blush for his country. Murder, robbery & rape of mothers & daughters, in the presence of the tied up males of their families, have been common all along the Rio Grande…. Truly it would seem unchristian & cruel to let loose upon any people—even savages—such unbridled persons—freebooters, &c., &c….”– Scott writing the Secretary of War after visiting Taylor’s army

(Weigley, “History,” 187-188).

Limited War

• Scott will carry his ideas about limited war into the Civil War with his Anaconda Plan

• Many Federals, such as George McClellan, will advocate a strategy of conciliation toward the Confederacy

• Such an approach will be rejected and the Civil War will become increasingly total– Pope’s General Orders– Emancipation Proclamation– Conscription– Suspension of some civil liberties– Sherman’s March to the Sea

Limited War: Changing Times

• “… while Scott was the preeminent military strategist of the first half of the nineteenth century, he occupied a lonely plateau in more senses than one: that at the zenith of his powers he was already a museum piece, a soldier of an age gone by whose perceptions of war and strategy had little influence on most of the very West Point graduates whose service in Mexico he so fulsomely praised, because the young graduates inhabited a new world of very different values from Scott’s, the military world of Napoleon” (Russell Weigley, American Way of War, 76).

Turning Movement

• Scott conducted amphibious landing at Vera Cruz and then had to move by land to Mexico City along a predictable, well-defended avenue of approach

• Wanted to avoid frontal assaults by maneuver

Turning Movement

• Maneuver– As both an element of combat power and a principle

of war, maneuver concentrates and disperses combat power to place and keep the enemy at a disadvantage

– Achieves results that would otherwise be more costly– Keeps enemies off balance by making them confront

new problems and new dangers faster than they can deal with them

• The form of maneuver that Scott relied on in Mexico was the turning movement

Turning Movement

• In a turning movement the attacking force seeks to avoid the enemy's principal defensive positions by seizing objectives to the enemy rear and causing the enemy to move out of his current positions or divert major forces to meet the threat.

• A major threat to his rear forces the enemy to attack or withdraw rearward, thus "turning" him out of his defensive positions.

Turning Movement: Cerro Gordo

• Scott wanted to avoid a costly frontal assault so he had Robert E. Lee and other engineers recon a possible route around Santa Anna’s flank

• Lee found a way to outflank the defenders, and Scott executed the first of several flanking movements in his march to Mexico City.

Turning Movements and the Civil War

• “The Mexican War created an informal, unwritten tactical doctrine—to turn the enemy.” (Archer Jones)– Civil War battles and campaigns that involved

turning movements include the Peninsula Campaign, Second Manassas, and Vicksburg

• Nonetheless the Civil War will also include many costly frontal attacks such as Fredericksburg and Pickett’s Charge

Technology: Rifles

• Two things that made these frontal attacks so costly are the rifled musket and the Minie Ball– A few volunteer units

like the Mississippi Rifles had rifles in Mexico, but the Regular Army stubbornly held to smoothbore muskets

At Buena Vista, Jefferson Davis commanded the Mississippi Rifles to “Stand Fast, Mississippians!”

Technology: Changing Times

• By the time of the Civil War, the rifled musket and the Minie ball will cause a change in military tactics– The defense will gain strength

relative to the offense– Artillery will loose its ability to

safely advance close to the enemy and breach holes in defenses

– Close-order formations will become dangerously vulnerable

Technology: Other Examples

• Steam-powered ships

• Ironclads

• Telegraph

• Railroads

• Balloons

Junior Officers: Rehearsal for the Civil War

• Approximately 194 Federal generals and 142 Confederate generals previously served in Mexico

• Lee, Jackson, Hill, Pickett, Longstreet, Beauregard, Bragg, etc

• Meade, Grant, Kearney, McClellan, Hooker, Pope, McDowell, etc

Junior Officers: Impact of West Pointers

• In 1817, Sylvanus Thayer replaced Captain Alden Partridge as superintendent of West Point and began reversing the damage Partridge had done.

• Thayer broadened and standardized the curriculum, established a system to measure class standing, organized classes around small sections, improved cadet discipline, created the office of commandant of cadets, and improved military training.

“The Father of the Military Academy”

Junior Officers: Impact of West Pointers

• By the time of the Mexican War, Thayer’s reforms had produced a generation of men who would fill the junior officers’ ranks in Mexico.

• These lieutenants and captains stood in sharp contrast to the older officers who had not benefited from a systematic military education and training.

• The impact of Thayer and West Point was readily apparent in Mexico.

West Point was founded in 1802 and was instrumental in training engineers in the 19th Century

Junior Officers: Impact of West Pointers

• Winfield Scott called his West Pointers his “little cabinet”

• Scott was unwavering in his acknowledgement of West Pointers declaring,– “I give it as my fixed opinion that but for our graduated

cadets the war between the United States and Mexico might, and probably would, have lasted some four or five years, with, in its first half, more defeats than victories falling to our share, whereas in two campaigns we conquered a great country and a peace without the loss of a single battle or skirmish.”

West Pointers in the Civil War

• West Pointers will play a key role in the Civil War– 151 Confederate and 294 Federal generals

were West Point graduates– Of the Civil War’s 60 major battles, West

Pointers commanded both sides in 55– A West Pointer commanded on one side in

the other five

Civil War: Causes

• Slavery• States rights vs centralized government• Agrarian vs industrialized way of life• Cultural differences

– By the time of the Civil War, “an entire generation of Southern young men… had come of age with a sense of Southern cultural identity, commitment to slaveholding, and a willingness to defend these values against a Northern culture” (Gary Gallagher)

Road to War

• “War is nothing but the continuation of policy with other means.”– Clausewitz

• Missouri Compromise (1820) -- Maine admitted as a free state and Missouri as a slave, but no other slave states from the Louisiana Purchase territory would be allowed north of Missouri’s southern boundary

Road to War• Nullification Crisis (1832) --

Responding to a tariff on manufactured goods, South Carolina declared a state can void any act of Congress it feels is unconstitutional

• Mexican War (1846-1848) -- viewed by some as a Southern attempt to expand slavery– Wilmot Proviso (1846) failed.

Would have formally renounced any intention to introduce slavery into lands seized from Mexico

John Calhoun argued that each state was sovereign and the Constitution was a compact among sovereign states.

Road to War (cont)• Compromise of 1850 dealt

with issues involving territories gained in the Mexican War and slavery– California admitted as a free

state– Slavery in New Mexico and

Utah territories to be determined by popular sovereignty

– Slave trade prohibited in the District of Columbia

– A more stringent fugitive slave law was passed that required all U.S. citizens to assist in the return of runaway slaves

Henry Clay, “the Great Compromiser,” introduces the Compromise of 1850

Road to War (cont)

• Kansas-Nebraska Act (1854) -- popular sovereignty; effectively overturns Missouri Compromise

• Harper’s Ferry and John Brown (1859)

• Lincoln elected (Nov 6, 1860)

• South Carolina votes to secede (Dec 20, 1860) – Mississippi, Alabama,

Louisiana, Georgia, Florida, and Texas follow

Road to War (cont)

• Lincoln takes office (March 4, 1861)

• Fort Sumter (April 12, 1861)

• Lincoln requests 75,000 three-month volunteers (April 15, 1862)– Virginia,

Arkansas, North Carolina, Tennessee secede

States in the Civil War

Objectives

• North– Restore Union

• Therefore couldn’t completely alienate or destroy the South or the Southern people

• South– Hold on to de facto

independence– Continue the

struggle long enough for the North to tire of it• Similar to

American colonists

Northern Strategy

• Secure border states• Still need to go on

offensive to win

• Scott’s Anaconda Plan• Blockade• Secure the Mississippi

River and cut the South in two

• Wait

• Capture Richmond• Anaconda Plan would

take too long• In June 1861, Lincoln

orders an advance on Richmond

Southern Strategy

• Defend at the border– Political pressure to defend all territory– Maintain legitimacy through territorial integrity– Protect slavery

• Offensive-defensive– Realize they don’t have the resources to defend

everywhere– Allow Northern thrust to develop– Determine the main axis– Concentrate and counterattack at an advantageous time

Comparison

• North– 20 million people– 110,000

manufacturing establishments

– 22,000 miles of railroad

– 75% of nation’s total wealth

– 16,000 man Army and 90 ship Navy

• South– 9 million people (5.5

million whites)– 18,000 manufacturing

establishments– 8,500 miles of railroad– Wealth lay in land and

slaves (non-liquid)– No existing military

Comparison

• North– Had to project forces

across large and hostile territory

– Requirement for offense

– Had to maintain supply lines

– Fighting to regain preexisting status quo

• South– Could take advantage

of interior lines– Could win by only

succeeding on the defense

– Friendly territory and population

– Fighting for homeland and independence

Next

• Fort Sumter, First Manassas, Early Amphibious Operations