Both Robert E. Lee and Ulysses S. Grant were young officers during the Mexican American War and while they were not commanders of troops in the field, they were both talented observers and came away wuth numerous "lessons learned" and real life combat experience from what they saw. Others worthy of mention but less well known include:
Braxton Bragg, General, CSA.
P.G.T. Beauregard, General, CSA,
Stonewall Jackson, Lieutenant General, CSA.
Edmund Kirby Smith,
John Joseph Abercrombie,
Barton Stone Alexander,
Robert Allen,
Robert Anderson,
Richard Heron Anderson, Lieutenant General CSA.
Lewis Addison Armistead, Brigadier General, CSA, died two days after Pickett's charge.
Lewis Golding Arnold,
John Gross Barnard,
Joseph K, Barnes, Surgeon General of the US Army,
William Farquhar Barry,
Samuel Beatty,
Francis Preston Blair, Jr.,
Henry Washington Benham,
William Plummer Benton,
John Milton Brannan,
John Cablell Breckinridge, Brigadier General, Secretary of War, CSA.
Benjamin William Brice,
William Thomas Harbaugh Brooks,
Robert Christie Buchanan,
Don Carlos Buell,
Ambrose Burnside,
Edward Canby, theonly General killed in the Indian Wars.
Samues Perry "Powhatan" Carter, who was also a Rear Admiral in the Navy,
Meriwether Lewis Clark, Brigadier General, CSA, son of William Clark.
Phillip St, George Cook, J.E.B. Stuart's Father in Law.
Samuel Cooper, General, CSA, Highest ranking Confederate General in the Civl War.
Washington Lafayette Elliot,
Abner Doubleday, Fired the first shot at Fort Sumter.
Nathan Bedford Forrest, Lieutenant General,CSA.
John Gray Foster.
John Charles Freemont,
George Washington Getty,
John Gibbon,
Charles Champion Gilbert,
George Gordon, General, CSA, Tennessee KKK leader after the Civil War,
Charles Griffin,
Schyler Hamilton, Grandson of Alexander Hamilton,
Winfield Scott Hancock,
Daniel Harvey Hill, Lieutenand General. CSA Postwar Georgia KKK leader,
Albert Sidney Johnston, General, CSA, Killed at Shiloh,
Joseph King Fenno Mansfield, Killed at Antietam, Sharpsburg, Maryland,
George Brinton McClelland, briefly General in Chief of the Union Army,
Irvin McDowell,
George Gordon Meade,
William "Bull Nelson, a former Navy Lieutenant at Veracruz, murdered by Jefferson Davis,
Joseph Warren Revere, Grandson of Paul Revere, US Naval and Mexican Army Officer.
Winfield Scott, General in Chief of the Army, Virgini Union Loyalist and creator of the Anaconda Plan to defeat the Confederacy, retired in 1861 at 75,
Truman Seymour.
Charles, Pomeroy Stone, later the Chief of Staff of the Egyptian Army.
Thomas John Wood.
John Ellis Wool, at the age of 77 and with 20 years time in grade as a Brigadier General was the oldest Civil War General Officer.
This is only a small sample of the General Officers who saw service in both the Mexican Americqan ane the US Civil War.
Do you mean 'Who served at the rank of General in both wars?' Probably Winfield Scott would be the only one of that seniority.
But if you mean 'Which Civil War Generals had served in Mexico?', the answer is that nearly all of the officers promoted at the outset of the Civil War were Mexico veterans, and it was taken as a standard mark of credibility.
Sherman was a rare case of an officer who had been in uniform at the time, but posted away from the action, in Northern California. Only through his good performance at Bull Run and his growing friendship with U.S. Grant did he overcome this handicap.
On the Confederate side, Jefferson Davis was made President, and effectively General-in-Chief, because of his respectable record as a Colonel in Mexico, fifteen years earlier. This did not translate into effective leadership at high levels.
Generals Winfield Scott and Sterling Price served in both wars as General Officers.
Many including both Grant and Lee.
There were many including both Lee and Grant.
In the Mexican War of 1846 "Remember the Alamo" the general for Mexico was Antonio Lopez de Santa Anna and for the United States was soon to be President General Zachary Taylor. The American President was James A. Polk. Many young officers fought in this war who would become major players in the American Civil War.
The War of 1812The Mexican-American WarThe American Civil WarThe Spanish American War
The most important long term result of the Mexican-American War wasn't the expansion of the United States by a third (if including Texas), but the experience gained by the American officers that fought in the war. I believe this because the same officers that fought in the Mexican-American War also fought in the American Civil War, which if it weren't for the Mexican-American War the officers in the Civil War might have had different tactics, which could have lead to a different outcome of the Civil War. This alternative outcome would have been the Southern United States successfully succeeding from the Union and the eventual takeover of the Northern and Southern United States by Britain, Spain, and France.
Command divisions
The Mexican, or its other name, the Mexican-US War, was in 1846. There is no direct connection to the US Civil War, other then that many of the generals of the Civil War, fought together and came to know each other.
There were many including both Lee and Grant.
In the Mexican War of 1846 "Remember the Alamo" the general for Mexico was Antonio Lopez de Santa Anna and for the United States was soon to be President General Zachary Taylor. The American President was James A. Polk. Many young officers fought in this war who would become major players in the American Civil War.
Zachary Taylor
Both Grant and Lee.
There were many Civil War Generals who served in the Mexican American War. Among them were Robert E. Lee, US Grant, William T. Sherman, Winfield Scott
The War of 1812The Mexican-American WarThe American Civil WarThe Spanish American War
The most important long term result of the Mexican-American War wasn't the expansion of the United States by a third (if including Texas), but the experience gained by the American officers that fought in the war. I believe this because the same officers that fought in the Mexican-American War also fought in the American Civil War, which if it weren't for the Mexican-American War the officers in the Civil War might have had different tactics, which could have lead to a different outcome of the Civil War. This alternative outcome would have been the Southern United States successfully succeeding from the Union and the eventual takeover of the Northern and Southern United States by Britain, Spain, and France.
The most important long term result of the Mexican-American War wasn't the expansion of the United States by a third (if including Texas), but the experience gained by the American officers that fought in the war. I believe this because the same officers that fought in the Mexican-American War also fought in the American Civil War, which if it weren't for the Mexican-American War the officers in the Civil War might have had different tactics, which could have lead to a different outcome of the Civil War. This alternative outcome would have been the Southern United States successfully succeeding from the Union and the eventual takeover of the Northern and Southern United States by Britain, Spain, and France.
From 1846 to 1848.
Command divisions
Ulysses S. Grant, Robert E. Lee, Braxton Bragg, Stonewall Jackson,