	Erdman started a construction company in 1946, which he incorporated in 1951 as Marshall Erdman & Associates. An integrated healthcare design-build company, Marshall Erdman & Associates grew rapidly, expanding into six different markets throughout the U.S. In early 2008, Marshall Erdman & Associates was purchased by Cogdell Spencer, a healthcare real estate investment trust, for $247 million. This part of Marshall's legacy is now traded on the NYSE as CSA.