Every single day a large swath of Miamians drive, dine, party or do business on Brickell Avenue. Many of them live there too, or in the nearby neighborhoods of The Roads or even Brickell Key. But only a few know much about the folks who have given the street its name: William and Mary Brickell, contemporaries of Julia Tuttle and Henry Flagler, who were on hand for the city’s founding.