Raleigh was established in 1788; it was intended as a capital before it was even built, and the city was designed and planned for that purpose.
Raleigh is often referred to as Raleigh/Durham, a misnomer that annoys citizens of both cities. Each location is unique and has a distinct identity. The airport is the cause, but anyone living in Raleigh, Durham or Chapel Hill will tell you that the only thing they have in common is the airport.