Abstract: Cosmological observations based on a wide variety of methods are in good agreement on the contents and history of the universe. The universe contains roughly 4% baryons, 22% of a new kind of matter we hope to understand with future particle physics experiments, and 74% of a new kind of pressure or energy that has yet to find explanation in fundamental theories. The universe began in a manner that produced variations in gravitational potential over a cosmological range of length scales. These variations, quantum mechanical in origin, seeded the eventual formation of cosmic structure. By combining new measurements of the polarization of the cosmic microwave background with measurements of the temperature anisotropy, WMAP has begun to probe the quantum mechanics of the early universe. We discuss the WMAP measurements and their interpretation. We have much more to learn from observations of the CMB. We conclude with a brief look at future experiments with an emphasis on ACT.