This proceedings contains over 300 papers presented at the Structures Congress 2009, "Don't Mess with Structural Engineers - Expanding Our Role", which took place in Austin, Texas from April 30 to May 2, 2009. The mission of this vital and necessary conference is to illustrate how structural engineering is adapting to the changing global economy, while advancing and redefining structural engineering in the areas of bridge and transportation structures, buildings, and research. The papers presented here cover: design and analysis of bridges; historic bridge preservation; structural design performance and serviceability of buildings; structural fire resistant design; collapse prevention design; and non-building and special structures.