North B Street The street which is now known as Constitution Avenue was originally called North B Street, following the District's street naming system. For much of the 1800s, there was no road, but instead was the site of the <a href="http://mallhistory.org/items/show/41">City Canal</a>. When the canal was covered over and paved, the street was named B. The street was renamed Constitution Avenue in 1931, following improvements to the road. David Rumsey Map Collection. <a href="http://www.davidrumsey.com/luna/servlet/s/x08h49">View original</a>. 1931 (renamed) <a href="/items/browse?advanced%5B0%5D%5Belement_id%5D=38&advanced%5B0%5D%5Btype%5D=is+exactly&advanced%5B0%5D%5Bterms%5D=1860-1889">1860-1889</a> <a href="/items/browse?advanced%5B0%5D%5Belement_id%5D=38&advanced%5B0%5D%5Btype%5D=is+exactly&advanced%5B0%5D%5Bterms%5D=1920-1949">1920-1949</a>