The 1920 opening of the Michigan Avenue Bridge, which was part of the efforts to enact the Burnham Plan of 1909, as well as the economic boom of the 1920s, brought wealth to the eastern sector of the Near North Side and paved the way for a luxury shopping district on North Michigan Avenue. Investors built high-rise apartment buildings such as those in the East Lake Shore Drive Historic District, and elaborate hotels. The Bridge connected to a North Michigan avenue that served as a replacement for the former Pine Street which hosted warehouses and factory buildings near the river, and large mansions and rowhouses in northward sections in the neighborhoods of McCormickville and Streeterville. Magnificent Mile architecture during the economic boom of the 1920s emphasized historicist architectural styles such as Beaux-Arts classicism, Gothic revival, and vertical-style modernism. The buildings redefined the Chicago skyline with stylistic variation that gave new meaning to urban context and design compatibility.