We've been collecting your questions for more than two months now and one topic keeps coming up: the Valley's population. So we're taking two episodes to answer your population-related questions.  In this week's episode, we look at how Phoenix and the Valley got so big. When did we start growing? And what fueled that growth?  Be sure to listen next week when we explore the future population of the Valley.  Want your question about metro Phoenix answered? Submit it at valley101podcast.azcentral.com. And follow us on Twitter @valley101pod.