One of the most important open issues in astronomy is the assembly of galactic disks. My group and I approach this subject from an observational perspective, tracing the kinematic evolution of star-forming galaxies since a redshift of 2, or over the last 10 billion years of the universe. I will discuss recent results that show the progressive (and mass-dependent) assembly of disk galaxies over this time period. These results strongly challenge the traditional analytic model of galaxy formation and provide an important benchmark for simulations. I will also demonstrate techniques we have developed to decipher observations of the and morphologies of high redshift galaxies using hydrodynamic simulations.