For the first half of the 19th century, the portion of St. Charles above
Lee Circle (then "Tivoli Circle") was known as Nyades Street. The lower portion was and is an important corridor in the
Central Business District. Historically significant buildings include
Gallier Hall, which was City Hall until the 1950s. The street was laid out atop a slight rise, the remains of an old natural
levee, in connection with the construction of the
New Orleans and Carrollton Railroad, which became the
St. Charles Streetcar Line. The long traffic avenue originally used for horse-drawn buggies and wagons, with public rail transit running down the center, helped fuel the development of Uptown in the 19th century. In 1889, writer
Martha R. Field observed that "St. Charles Avenue is seven miles long, and is paved with
asphalt its entire length" and was lined "with beautiful homes." St. Charles Avenue was the favored site for construction of
mansions by the wealthy from the mid 19th century through the early years of the 20th century. A number of the old mansions were torn down in the mid- and late 20th century, until the area was declared an historic district. Many of the surviving ones have been divided into condominiums or rental apartments; others have been utilized as businesses, small hotels, and a library, while some remain individually-owned residences. In early 1999, an effort by the
New Orleans Police Department was made to clean up the Avenue and the blocks north, which were beginning to show signs of
seediness. The illegal drug industry was pushed back into
Central City. During the 2005 flooding of the majority of New Orleans due to levee failures caused by
Hurricane Katrina, St. Charles Avenue and the portion of Uptown closer to the Mississippi River escaped significant flooding. ==Prominent buildings==