RTKL was a global architecture, planning and design firm. The firm was founded in 1946 by Archibald Rogers and Francis Taliaferro in Rogers’ grandmother’s basement in Annapolis and grew to be one of the largest architectural firms in the world prior to its acquisition by Arcadis NV in 2007. In October 2015, RTKL was formally merged with another Arcadis subsidiary, Seattle-based Callison, to form CallisonRTKL headquartered in Baltimore. "RTKL" comes from the initials of the initial members: Rogers Taliaferro Kostritsky Lamb. The firm was founded by Archibald Rogers in his grandmother’s basement in Annapolis. Francis Taliaferro joined shortly afterwards. In 1949, the pair hired Charles Lamb, whose design for the Anne Arundel County Girl Scouts Teepee Lodge gained the firm national attention by winning an award from the American Institute of Architects.