Richard Caswell's career began at an early age. At only the age of 17, he was appointed as an apprentice to Surveyor General James Mackilwean, and learned the art of surveying, a very profitable trade in the Eighteenth Century. Surveyors would purchase newly opened land as the frontier expanded and sell tracts to settlers at higher prices. Colonists held surveyors in suspicion but Caswell remained popular with the people throughout his political career. Today, students visiting the Richard Caswell Memorial can experience Eighteenth Century surveying with a hands-on activity with authentic instruments.

Caswell's career landed him in numerous government offices and eventually into the Colonial Assembly, the North Carolina legislature under British rule. Caswell is appointed Deputy Clerk of Johnston County at the age of 18, in 1748, and then Surveyor General in 1750. He presented a bill to establish the town of Kingston, North Carolina's 20th official town, and applied his surveying skills when planning the town layout. Caswell Street in present-day Kinston links the streets' names honoring the families of his wives: Mackilwean Street for the family of the then-deceased Mary Mackilwean and Herritage Street for the family of his current wife, Sarah. In 1784, after the Revolution, Caswell initiated the new town name of Kinston to sever ties to its namesake King George III.

When the relationship between the British government and the American Colonies strained, Caswell attended the First Continental Congress in 1774 and the Second Continental Congress in 1775. John Adams said of him, "We always looked to Richard Caswell for North Carolina. He was a model man and a true patriot." Royal governor Josiah Martin held a less flattering opinion of him, calling him "the most active tool of sedition." Caswell presided over the Fourth Provincial Congress, preventing him from participating in the drafting and signing of the Declaration of Independence. In November 1776 Caswell presided over the committee that drafted the state Constitution in the Fifth Provincial Congress. He was appointed acting governor in December 1776 and elected governor in April of 1777, by the First General Assembly. This was the first of three one-year terms. He also entertained the Marquis de Lafayette and Baron Johann de Kalb in New Bern.

After the Revolutionary War, Caswell served North Carolina as Controller General (Treasurer) and faced the difficult task of settling the state's post-war finances. He served again as governor for three one-year terms between 1785-1788. During the term of Caswell's predecessor Alexander Martin, North Carolina territories west of the Blue Ridge split from the state and formed the new state of Franklin. While Governor Martin had pursued an aggressive policy of intimidation, Caswell was more diplomatic towards the "Franklinites." Through delicate negotiations and peacekeeping, he prevented civil war and the state of Franklin again reunited with North Carolina. In 1789, these lands were ceded to the Union as the state of Tennessee. Illness prevented Caswell from participating in the 1786 Constitutional Convention, and he sent William Blount—who favored the adoption of the Constitution over the Articles of Confederation—in his stead. In 1789 Caswell was elected Speaker of the Senate in the North Carolina Assembly. On 5 November of that same year he suffered a stroke while in session at Fayetteville; he died five days later.