The earliest mention of regular gatherings by Explorers Club members in the Washington, D.C., area was a 1924 Explorers Club news note describing, an “excellent lecture program being conducted in Washington, DC”. In 1937, active members of The Explorers Club living in the Washington, D.C., area established The Explorers Club Washington Round Table Group.

This name was subsequently shortened to Explorers Club Washington Group or ECWG. Col. H.T. Cowling of the U.S. Army Air Corps, who was a student of Tibetan culture, initially led the organization in the early years, approximately 20 members met monthly at the Army-Navy Club or the Cosmos Club, where the ECWG continues to hold its monthly dinners.

Other early members included Alexander Wetmore and Waldo L. Schmitt of the Smithsonian Institution; R. Harvey Sargent and Gerald Fitzgerald of the U.S. Geological Survey; Dr. Isaiah Bowman of Johns Hopkins University; and Dr. Roy L Sexton (father of the late Roy L. Sexton, Jr., former ECWG archivist).

An ECWG tradition is the annual Bombash each fall, which is a now a weekend trip for leisurely exploration of a historic destination in the Middle Atlantic states. The name goes back to the “Bombashes,” which were one-day crab and oyster feasts that Edward L. Sweeney held at his Gibson Island, Maryland, estate. Sweeney was The Explorers Club president from 1965 until 1967. He was largely responsible for the Club’s national and international expansion and the Club’s Sweeney Medal is named for him.

In 1990 the Internal Revenue Service granted the ECWG 501(c) (3) status, which means gifts to the Group are tax deductible. In 1994 the ECWG became incorporated in Delaware. Membership in the ECWG is open to any active Explorers Club member who lives in Washington, D.C., Maryland, Virginia, or West Virginia.

ECWG membership for Explorers Club members who live elsewhere requires payment of normal $25 dues to the ECWG.