Saul Ewing LLP, the Philadelphia-based law firm, and Chicago-based Arnstein & Lehr merged effective September 1.

Now known as Saul Ewing Arnstein & Lehr, the new firm will have more than 400 employees.

There is no overlap in their footprint, according to The Legal Intelligencer. Saul Ewing’s 15 offices stretch down the East Coast from Boston to Washington. Arnstein & Lehr’s main office is in Chicago and it has 50-plus lawyers in Florida cities.

“For many years, Saul Ewing looked for the right growth opportunity that would build on our special culture and passion for putting clients first,” said Barry F. Levin, who will serve as the combined firm’s managing partner. “We immediately found that same client commitment with Arnstein & Lehr.”

Jeffrey B. Shapiro, the former managing partner of Arnstein & Lehr who will lead the firm’s Miami office said, “We are dedicated to being one of America’s great law firms.”

Saul Ewing and Arnstein & Lehr have several shared clients.

Saul Ewing joins the merger with 11 offices from Boston to Washington, D.C., and west to Pittsburgh. The merger deepens its bench in several key practice areas, including bankruptcy, business and finance, litigation, and real estate. It opens up new practice areas including immigration and foreign investment.

Based in Illinois and Florida, Arnstein & Lehr is one of the country’s oldest law firms. Since its founding in 1893, the firm has served clients in the U.S. and abroad in five main practice areas – business, litigation, local government, tax and estate planning and real estate. The merger provides the firm with a long-sought presence on the East Coast and strengthens its intellectual property bench.