The Independent School League includes Washington, D.C. and part of what states?
Independent School League (Washington, D.C. area): The Independent School League or ISL is a group of seventeen preparatory schools located in the Washington metropolitan area of the United States that compete with each other athletically. Washington metropolitan area:  The area includes all of the federal district and parts of the U.S. states of Maryland and Virginia, along with a small portion of West Virginia.
Maryland and Virginia, along with a small portion of West Virginia