Lockhouse B

In 1837 an extension of the C&O Canal was completed to join the Washington City Canal near present day Constitution and 17th. A triangular basin with an opening to the river was built and the C&O Canal extension came in on the west while the Washington City Canal came in on the east. The locktender at the lockhouse, known as Lockhouse B in the C&O Canal Company records, likely controlled the locks at the entrances to both canals. As the western Mall and Constitution Avenue were developed, the lockhouse was moved a short distance and the high chimneys replaced with low ones.