Area code 904 serves northeastern Florida, including the city of Jacksonville, as well as St. Augustine, Fernandina Beach, and Orange Park. Created in 1965 as a split from area code 305, 904 originally covered the entire northern portion of Florida until further splits formed 352, 850, and 386. Jacksonville, the largest city by area in the U.S., anchors this region and drives its economic activity through shipping, finance, and healthcare. The 904 code is strongly associated with North Florida identity and pride, often used in local events and branding. Despite population growth, 904 has remained a single area code since 2001. It continues to reflect a mix of Southern heritage, coastal charm, and metropolitan growth.