Brickell was settled in the modern era in the mid-19th century by early pioneers, growing to become Miami's "Millionaire's Row" in the early 20th century after the construction of lavish mansions along Brickell Avenue by Mary Brickell; both the avenue and neighborhood were named for Mary and her husband, William Brickell. By the 1970s, office towers, hotels and apartments began replacing the historic mansions. Brickell overtook the city's historic central business district to the north, as one of the largest financial districts in the United States. With a fast-growing residential population, Brickell is Miami's most dense neighborhood, with a 2010 population of about 31,000.