Short answers, pulled from the story.
North Carolina seceded in response to Abraham Lincoln's April 15 proclamation that requested 75,000 troops from all Union states. A popular vote in February 1861 on the issue of secession was won by unionists but not by a wide margin before this shift occurred.
General Joseph E. Johnston surrendered his Confederate army at Bennett Place near Durham to William Tecumseh Sherman in April 1865. This surrender essentially ended the war in the Eastern Theater and involved the last remaining major Confederate army.
African Americans across the state and white North Carolinians who disagreed with eastern planters helped number around 15,000 troops who served in the Union Army. These forces included groups like the Heroes of America which numbered nearly 10,000 men.
The major port of Wilmington channeled many vital supplies through defiance of the Union blockade throughout the war. The Department of North Carolina seized Wilmington in 1865 when it was still the state's largest city.
North Carolina ratified the Fourteenth Amendment on the 4th of July 1868. The North Carolina General Assembly of 1868 and 1869 readmitted North Carolina to the Union following this ratification.