Insights into the high-redshift Universe using Spitzer and Local Galaxies // How do the first galaxies form? What is their connection to reionization? With today’s large samples of galaxies at z > 5, this is one of the burning question in modern astrophysics. Current spectrographs are not able to probe the spectral properties of the very first galaxies until the advent JWST. However, by combining deep Spitzer data with detailed studies of local galaxies we can probe the formation of the first galaxies in depth and provide the optimal samples for follow-up with JWST as well as other upcoming facilities. My talk will focus on what we learn pre-JWST about the properties and formation of the first galaxies.