Title: The Mass Assembly History of Field Galaxies of Known Morphology Chris Conselice California Institute of Technology Abstract: New space based surveys with Hubble, such as the Hubble Deep Field and GOODS, combined with ground based data are allowing us to determine how galaxy populations change over cosmic time. This empirical information can be used to construct the formation history of galaxies. An important approach to this problem is understanding how measurable properties of galaxies, such as masses, luminosities, sizes and morphologies change from initial galaxy formation until the present day, and how these characteristics are related to modes of formation, such as galaxy merging. I will discuss these issues, including how these observations compare with physically based models of galaxy formation. >