6th St and Constitution Ave NW Enter or exit from Constitution Avenue, 4th Street, or Madison Drive on the National Mall. 1401 Constitution Avenue, NW U.S. Department of Commerce Washington, DC 20230.Constitution Avenue, NW, Washington, DC 20210. INSTRUCTIONS FOR FORM LM-4. Article IV of the Arizona Constitution is entitled Legislative Department. The legislative authority of the state shall be vested in the legislature, consisting of a senate and a house of representatives. America's National Independence Day Parade takes place annually on July 4th at am in Washington, DC, on Constitution Avenue from 7th to 17th Street. Use the addresses listed below. At headquarters, we use one address for all regular mail and specific building addresses for packages. The Constitution Avenue and John Marshall Park entrances are open from am to pm.