[2] Beaufort County is part of the Hilton Head Island-Bluffton-Port Royal, SC Metropolitan Statistical Area.

[3] The county's northern portions have also grown steadily, due in part to the strong federal military presence around the city of Beaufort.

The county's two portions are connected by the Broad River Bridge, which carries South Carolina Highway 170.

Beaufort County has been identified as the most at-risk county in the contiguous United States for combined damage from climate change in the medium term, largely due to high wet-bulb temperatures, economic and farm crop damages, and sea level rise.

The plantations on the Sea Islands had large concentrations of slaves that had infrequent and limited interaction with white people.

Slaves began to organize schools and other parts of their communities early in the war in this county, especially on the islands.

The Army founded Mitchellville on Hilton Head by March 1863 as a village where black people could practice self-governance; by 1865, it had 1,500 residents.

[5] When freedmen were granted citizenship and the franchise after the American Civil War by constitutional amendments, most joined the Republican Party.

[5] Beaufort County had many prominent black leaders, such as Robert Smalls, Jonathan Jasper Wright, William James Whipper, Julius I. Washington, and Thomas E.

[5] Increasing violence during election campaigns in the state from 1868 on was used by white insurgents and paramilitary groups to suppress black voting; results were also dependent on fraud.

[5] From 1900 through 1950, Beaufort County's economy suffered from the decline in agriculture, which together with oppressive social conditions of Jim Crow contributed to many African Americans making a Great Migration out of the South.

Southern Democrats in Congress helped gain the establishment of military installations in the county and state, which added more population and stimulated area jobs in the second half of the 20th century.

In addition, vacation and resort areas were developed that attracted increasing numbers of tourists through the winter season, and then others all year-round as retirees.

Even in the first half of the 20th century, Beaufort was routinely one of the counties in South Carolina which gave the Republicans the highest percentage of the vote.

In 1920, for example, Republican nominee Warren G. Harding won only 4% of the total vote in South Carolina, but 36% in Beaufort County.

[25] Beaufort County is included within the Hilton Head Island-Bluffton-Port Royal, SC Metropolitan Statistical Area which had an estimated population of 232,523 in 2023.