The birth of the first stars, black holes and galaxies heralded the end of the cosmic Dark Ages and the beginning of the Cosmic Dawn. The light from these objects heated and ionized almost every atom in existence, culminating in the Epoch of Reionization: the final major phase change of the Universe. This final frontier of astrophysical cosmology is undergoing a transition from an observationally-starved epoch to a "Big Data" field. This process will culminate with interferometric observations of the redshifted 21-cm line, eventually providing a 3D map of the first billion years of our Universe. I will discuss the recent clues to reionization, obtained from the CMB, high-redshift galaxies, and quasars. Nevertheless, the first generations of galaxies are unlikely to be seen even with the most powerful upcoming telescopes. However, their properties can be interpreted from the timing and patterns of the 21-cm signal. Innovative statistical and machine learning techniques have been developed to tap into the physical bounty of the cosmic 21-cm signal, ultimately allowing us to understand the properties of the first generations of galaxies.