Union Army in the context of "Sherman's March to the Sea"

New Jersey is a state located in both the Mid-Atlantic and Northeastern regions of the United States. Located at the geographic hub of the heavily urbanized Northeast megalopolis, it is bordered to the northwest, north, and northeast by New York State; on its east, southeast, and south by the Atlantic Ocean; on its west by the Delaware River and Pennsylvania; and on its southwest by Delaware Bay and Delaware. At 7,354 square miles (19,050 km), New Jersey is the fifth-smallest state in land area. According to a 2024 U.S. Census Bureau estimate, it is the 11th-most populous state, with over 9.5 million residents, its highest estimated count ever. The state capital is Trenton, and the state's most populous city is Newark. New Jersey is the only U.S. state in which every county is deemed urban by the U.S. Census Bureau. It is the most densely populated U.S. state.

New Jersey was first inhabited by Paleo-Indians as early as 13,000 BC. The Lenape were the dominant Indigenous group when Europeans arrived in the early 17th century, and they were subdivided into dialectal groups such as the Munsee, in the north, and the Unami and the Unalachtigo, elsewhere. Dutch and Swedish colonists founded the first European settlements in the state, with the British later seizing control of the region and establishing the Province of New Jersey, named after Jersey. The colony's fertile lands and relative religious tolerance drew a large and diverse population. New Jersey was among the Thirteen Colonies that supported the American Revolution, hosting several pivotal battles and military commands in the American Revolutionary War earning the title, "Crossroads of the American Revolution." New Jersey remained in the Union during the American Civil War and provided troops, resources, and military leaders in support of the Union Army. After the war, the state emerged as a major manufacturing center and a leading destination for immigrants, helping drive the Industrial Revolution in the U.S. New Jersey was the site of many industrial, technological, and commercial innovations. Many prominent Americans associated with New Jersey have proven influential nationally and globally, including in academia, advocacy, business, entertainment, government, military, non-profit leadership, and other fields.

Louisiana was a dominant population center in the southwest of the Confederate States of America, controlling the wealthy trade center of New Orleans, and contributing the French Creole and Cajun populations to the demographic composition of a predominantly Anglo-American country. In the antebellum period, Louisiana was a slave state, where enslaved African Americans had comprised the majority of the population during the eighteenth-century French and Spanish dominations. By the time the United States acquired the territory (1803) and Louisiana became a state (1812), the institution of slavery was entrenched. By 1860, 47% of the state's population were enslaved, though the state also had one of the largest free black populations in the United States. Much of the white population, particularly in the cities, supported slavery, while pockets of support for the U.S. and its government existed in the more rural areas.

Louisiana declared that it had seceded from the Union on January 26, 1861. Civil-War era New Orleans, the largest city in the South, was strategically important as a port city due to its southernmost location on the Mississippi River and its access to the Gulf of Mexico. The U.S. War Department early on planned for its capture. The city was taken by U.S. Army forces on April 25, 1862. Because a large part of the population had Union sympathies (or compatible commercial interests), the U.S. government took the unusual step of designating the areas of Louisiana then under U.S. control as a state within the Union, with its own elected representatives to the U.S. Congress. For the latter part of the war, both the U.S. and the Confederacy recognized their own distinct Louisiana governors. Similarly, New Orleans and 13 named parishes of the state were exempted from the Emancipation Proclamation, which applied exclusively to states in rebellion against the Union.

The Lieber Code (General Orders No. 100, April 24, 1863) was the military law that governed the wartime conduct of the Union Army by defining and describing command responsibility for war crimes and crimes against humanity; and the military responsibilities of the Union soldier fighting in the American Civil War (April 12, 1861 – May 26, 1865) against the Confederate States of America (February 8, 1861 – May 9, 1865).

The General Orders No. 100: Instructions for the Government of the Armies of the United States in the Field (Lieber Code) were written by Franz Lieber, a German lawyer, political philosopher, and combat veteran of the Napoleonic Wars.

New Hampshire (/ˈhæmpʃər/ HAMP-shər) is a state in the New England region of the Northeastern United States. It borders Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec to the north. Of the 50 U.S. states, New Hampshire is the seventh-smallest by land area and the tenth-least populous, with a population of 1,377,529 residents as of the 2020 census. Concord is the state capital and Manchester is the most populous city. New Hampshire's motto, "Live Free or Die", reflects its role in the American Revolutionary War; its nickname, "The Granite State", refers to its extensive granite formations and quarries. It is well known for holding the first primary in the U.S. presidential election cycle, and its resulting influence on American electoral politics.

New Hampshire was inhabited for thousands of years by Algonquian-speaking peoples such as the Abenaki. Europeans arrived in the 17th century, with the English establishing some of the earliest non-indigenous settlements. The Province of New Hampshire was established in 1629, named after the English county of Hampshire. Following tensions between the British colonies and the crown in the 1760s, New Hampshire saw one of the earliest acts of rebellion, with the seizing of Fort William and Mary from the British in 1774. In 1776, it became the first of the British North American colonies to establish an independent government and state constitution. It signed the United States Declaration of Independence and contributed troops, ships, and supplies in the war against Britain. In 1788, it was the 9th state to ratify the U.S. Constitution, bringing it into effect. Through the mid-19th century, New Hampshire was an active center of abolitionism, and fielded close to 32,000 Union soldiers during the U.S. Civil War. Afterwards the state saw rapid industrialization and population growth, becoming a center of textile manufacturing, shoemaking, and papermaking; the Amoskeag Manufacturing Company in Manchester was the largest cotton textile plant in the world. French Canadians formed the most significant influx of immigrants, and a quarter of New Hampshire residents have French American ancestry.

The Regular Army of the United States succeeded the Continental Army as the country's permanent, professional land-based military force. In modern times, the professional core of the United States Army continues to be called the Regular Army (often abbreviated as "RA"). From the time of the American Revolution until after the Spanish–American War, state militias and volunteer regiments organized by the states (but thereafter controlled by federal authorities and federal generals in time of war) supported the smaller Regular Army of the United States. These volunteer regiments came to be called United States Volunteers (USV) in contrast to the Regular United States Army (USA). During the American Civil War, about 97 percent of the Union Army was United States Volunteers.

In contemporary use, the term Regular Army refers to the full-time active component of the United States Army, as distinguished from the Army Reserve and the Army National Guard. A fourth component, the Army of the United States, has been inactive since the suspension of the draft in 1973 and the U.S. armed forces became an all-volunteer armed force.

South Carolina was the first state to secede from the Union in December 1860, and was one of the founding member states of the Confederacy in February 1861. The bombardment of the beleaguered U.S. garrison at Fort Sumter in Charleston Harbor on April 12, 1861, is generally recognized as the first military engagement of the war. The retaking of Charleston in February 1865, and raising the flag (the same flag) again at Fort Sumter, was used for the Union symbol of victory.

South Carolina provided around 60,000 troops for the Confederate Army. As the war progressed, former slaves and free blacks of South Carolina joined U.S. Colored Troops regiments for the Union Army (most Blacks in South Carolina were enslaved at the war's outset). The state also provided uniforms, textiles, food, and war material, as well as trained soldiers and leaders from The Citadel and other military schools. In contrast to most other Confederate states, South Carolina had a well-developed rail network linking all of its major cities without a break of gauge.

The American state of Virginia became a prominent part of the Confederacy when it joined during the American Civil War. As a Southern slave-holding state, Virginia held the state convention to deal with the secession crisis and voted against secession on April 4, 1861. Opinion shifted after the Battle of Fort Sumter on April 12, and April 15, when U.S. President Abraham Lincoln called for troops from all states still in the Union to put down the rebellion. For all practical purposes, Virginia joined the Confederacy on April 17, though secession was not officially ratified until May 23. A Unionist government was established in Wheeling and the new state of West Virginia was created by an act of Congress from 50 counties of western Virginia, making it the only state to lose territory as a consequence of the war. Unionism was indeed strong also in other parts of the State, and during the war the Restored Government of Virginia was created as rival to the Confederate Government of Virginia, making it one of the states to have 2 governments during the Civil War.

In May, it was decided to move the Confederate capital from Montgomery, Alabama, to Richmond, Virginia, in large part because, regardless of the Virginian capital's political status, its defense was deemed vital to the Confederacy's survival. On May 24, 1861, the U.S. Army moved into northern Virginia and captured Alexandria without a fight. Most of the battles in the Eastern Theater of the American Civil War took place in Virginia because the Confederacy had to defend its national capital at Richmond, and public opinion in the North demanded that the Union move "On to Richmond!" The successes of Robert E. Lee in defending Richmond are a central theme of the military history of the war. The White House of the Confederacy, located a few blocks north of the State Capitol, became home to the family of Confederate leader, former Mississippi Senator Jefferson Davis.

The American Civil War significantly affected Tennessee, with every county witnessing combat. During the War, Tennessee was a Confederate state, and the last state to officially secede from the Union to join the Confederacy. Tennessee had been threatening to secede since before the Confederacy was even formed, but would not officially do so until after the fall of Fort Sumter when public opinion throughout the state drastically shifted. Tennessee seceded in protest to President Lincoln's April 15 Proclamation calling forth 75,000 members of state militias to suppress the rebellion. Tennessee provided the second largest number of troops for the Confederacy, and would also provide more southern unionist soldiers for the Union Army than any other state within the Confederacy.

In February 1862, some of the war's first serious fighting took place along the Tennessee and Cumberland rivers, recognized as major military highways, and mountain passes such as Cumberland Gap were keenly competed-for by both sides. The Battle of Shiloh and the fighting along the Mississippi brought glory to the then little-known Ulysses S. Grant, while his area commander Henry Halleck was rewarded with a promotion to General-in-Chief. The Tullahoma campaign, led by William Rosecrans, drove the Confederates from Middle Tennessee so quickly that they did not take many casualties, and were strong enough to defeat Rosecrans soon afterward. At Nashville in December 1864, George Thomas routed the Army of Tennessee under John Bell Hood, the last major battle fought in the state.

The Ten Percent Plan, formally the Proclamation of Amnesty and Reconstruction (13 Stat. 737), was a United States presidential proclamation issued on December 8, 1863, by United States President Abraham Lincoln, during the American Civil War. By this point in the war (nearly three years in), the Union Army had pushed the Confederate Army out of several regions of the South, and some Confederate states were ready to have their governments rebuilt. Lincoln's plan established a process through which this postwar reconstruction could come about.