Arthur J. Gallagher & Co. has acquired Chantilly, Virginia-based The Andersen Group. The Andersen Group is a retail insurance agency with a specialty in serving non-profit trade associations, government contractors and engineering services companies in the greater Washington DC region. Founder Frank Andersen and his team will operate under the direction of Bumpy Triche, head of Gallagher's Mid-South retail property and casualty brokerage operations. J. Patrick Gallagher, CEO, comments: "Frank and his team are highly respected, and their market expertise will enhance our capabilities in the region."