Military leadership in the American Civil War was vested in both the political and the military structures of the belligerent powers. The overall military leadership of the United States during the Civil War was ultimately vested in thePresident of the United States as constitutional commander-in-chief, and in the political heads of the military departments he appointed. Most of the major Union wartime commanders had, however, previous regular army experience. A smaller number of military leaders originated from theUnited States Volunteers. Some of them derived from nations other than the United States.
In the Southern Confederacy, the constitutional commander-in-chief was educated atWest Point and had served in the Mexican War. Many officers in the United States Army, most of them educated at West Point at the expense of the United States, and having taken anoath of allegiance to the same, joined the rebellion against it. Several significant Confederate military leaders emerged from state unit commands. Some military leaders derived from countries other than the United States.
PresidentAbraham Lincoln wasCommander-in-Chief of the Unionarmed forces throughout the conflict; after his April 14, 1865assassination,Vice PresidentAndrew Johnson became the nation's chiefexecutive.[1] Lincoln's firstSecretary of War wasSimon Cameron;Edwin M. Stanton was confirmed to replace Cameron in January 13, 1862.Thomas A. Scott wasAssistant Secretary of War.Gideon Welles wasSecretary of the Navy, aided byAssistant Secretary of the NavyGustavus Fox.[2]
| Title | Name | Tenure | Notes | |
|---|---|---|---|---|
Commander-in-Chief |  | Abraham Lincoln | March 4, 1861 – April 15, 1865 (1,464 days during the war) | assassinated April 14, 1865; died April 15, 1865 |
 | Andrew Johnson | April 15, 1865 – March 4, 1869 (24 days during the war) | Declared the armed conflict to be "virtually" ended onMay 9, 1865[3] | |
Secretary of War | .jpg) | Simon Cameron | March 5, 1861 – January 14, 1862 (277 days during the war) | resigned January 14, 1862 |
.jpg) | Edwin Stanton | January 20, 1862 – May 28, 1867 (1,205 days during the war) | previouslyU.S. Attorney General | |
Secretary of Navy | .jpg) | Gideon Welles | March 7, 1861 – March 4, 1869 (1,488 days during the war) | |
When the war began, the Americanstanding army or "Regular army" consisted of only 1080commissioned officers and 15,000enlisted men.[4] Although 142 regular officers became Union generals during the war, most remained "frozen" in their regular units. That stated, most of the major Union wartime commanders had previous regular army experience.[5] Over the course of the war, theCommanding General of the United States Army was, in order of service,Winfield Scott,George B. McClellan,Henry Halleck, and finally,Ulysses S. Grant.
Commanding Generals, U.S.A.
| No. | Name | Tenure | Notes | |
|---|---|---|---|---|
| 1 | .jpg) | BrevetLieutenant generalWinfield Scott | July 5, 1841 – November 1, 1861 | retired November 1, 1861 |
| 2 |  | Major generalGeorge McClellan | November 1, 1861 – March 11, 1862 | Commanded theArmy of the Potomac in addition to serving as Commanding General. Relieved of duty as Commanding General on March 11, 1862. |
| 3 | vacant | March 11, 1862 – July 23, 1862 | responsibilities of Commanding General fulfilled by President Lincoln | |
| 4 | .jpg) | Major generalHenry Halleck | July 23, 1862 – March 9, 1864 | Appointed Chief of Staff of the General Headquarters in Washington DC on March 12, 1864[6] |
| 5 | .jpg) | GeneralUlysses S. Grant | March 9, 1864 – March 4, 1869 | first full rank General in the U.S. Army |
Under theUnited States Constitution, eachstate recruited, trained, equipped, and maintained localmilitia;regimental officers were appointed andpromoted by stategovernors. After states answered Lincoln's April 15, 1861, ninety-day call for 75,000 volunteer soldiers, mostUnion states' regiments andbatteries became known asUnited States Volunteers to distinguish between state-raised forces and regular army units. Unionbrigade-level officers (generals) could receive two different types of Federalcommissions: U.S. Army or U.S. Volunteers (ex:Major General, U.S.A. as opposed to Major General, U.S.V.). While most Civil War generals held volunteer orbrevet rank, many generals held both types of commission; regular rank was considered superior.[7]
Reflecting the multi-national makeup of the soldiers engaged, some Union military leaders derived from nations other than the United States.
The rapid rise of theUnited States Navy during the Civil War contributed enormously to the North's ability to effectivelyblockade ports and Confederate shipping from quite early in the conflict. Handicapped by an aging 90 ship fleet, and despite significant manpower losses to theConfederate Navy after secession, a massive ship construction campaign embracing technological innovations fromcivil engineerJames Buchanan Eads andnaval engineers likeBenjamin F. Isherwood andJohn Ericsson, along with four years' daily experience with modern naval conflict put the U. S. Navy onto a path which has led to today's world naval dominance.[8]
Commanding Officer, U.S.N.
| No. | Name | Tenure | Notes | |
|---|---|---|---|---|
| - | .jpg) | Flag OfficerCharles Stewart | March 2, 1859 – December 21, 1861 | Served as "Senior Flag Officer, U.S.N." until his retirement on 21 December 1861; promoted Rear Admiral on theRetired list July 16, 1862 |
| 1 | .jpg) | Vice AdmiralDavid Farragut | December 21, 1861 – August 14, 1870 | Commanded theWest Gulf Blockading Squadron in addition to serving as Commanding Officer. Promoted fullAdmiral on July 25, 1866 |
     |
Jefferson Davis was named provisionalpresident on February 9, 1861, and assumed similar commander-in-chief responsibilities as would Lincoln; on November 6, 1861, Davis was electedPresident of the Confederate States of America under theConfederate Constitution.Alexander H. Stephens was appointed asVice President of the Confederate States of America on February 18, 1861, and later assumed identical vice presidential responsibilities asHannibal Hamlin did. Several men served the Confederacy as Secretary of War, includingLeroy Pope Walker,Judah P. Benjamin,George W. Randolph,James Seddon, andJohn C. Breckinridge.Stephen Mallory was Confederate Secretary of the Navy throughout the conflict.[9]
| Title | Name | Tenure | Notes | |
|---|---|---|---|---|
Commander-in-Chief | .jpg) | Jefferson Davis | February 18, 1861 – May 5, 1865 | |
| Vice President | .jpg) | Alexander H. Stephens | February 11, 1861 – May 11, 1865 | |
Secretary of War | .jpg) | LeRoy Pope Walker | February 25, 1861 – September 16, 1861 | resigned September 16, 1861 |
.jpg) | Judah P. Benjamin | September 17, 1861 – March 24, 1862 | resigned March 24, 1862, to take appointment asCS Secretary of State | |
.jpg) | George W. Randolph | March 24, 1862 – November 15, 1862 | resigned November 15, 1862, for health reasons | |
.jpg) | James Seddon | November 21, 1862 – February 5, 1865 | resigned February 5, 1865 | |
 | Major GeneralJohn C. Breckinridge | February 6, 1865 – May 10, 1865 | ||
Secretary of Navy | .jpg) | Stephen Mallory | March 4, 1861 – May 2, 1865 | |
In the wake ofsecession, many regular officers felt they could not betray loyalty to their home state, and as a result some 313 of those officers resigned their commission and in many cases took up arms for the Confederate Army. Himself a graduate of West Point and a former regular officer, Confederate President Jefferson Davis highly prized these valuable recruits to the cause and saw that former regular officers were given positions of authority and responsibility.[10]
The land ofDavy Crockett andAndrew Jackson, the state military tradition was especially strong in southern states, some of which were until recently frontier areas. Several significant Confederate military leaders emerged from state unit commands.
While no foreign power sent troops or commanders directly to assist the Confederate States, some leaders derived from countries other than the United States.
The Confederate Navy possessed no extensiveshipbuilding facilities; instead, it relied on refitting captured ships or purchased warships fromGreat Britain. The South had abundantnavigableinland waterways, but after the Union built a vast fleet of gunboats, they soon dominated theMississippi,Tennessee,Cumberland,Red and other rivers, rendering those waterways almost useless to the Confederacy. Confederates did seize several Union Navy vessels in harbor after secession and converted a few intoironclads, like theCSSVirginia.Blockade runners were built and operated by British naval interests, although by late in the war the C.S. Navy operated some. A few new vessels were built or purchased in Britain, notably theCSSShenandoah and theCSSAlabama. These warships acted as raiders, wreaking havoc with commercial shipping. Aggrieved by these losses, in 1871 the U.S. government was awarded damages from Great Britain in theAlabama Claims.[8]
