(Always looking for more Podcasts to add to the list. Do you have a favorite?) 
"Presidential" - a Podcast from the Washington Post that goes into depth about every president! 
"Constitutional" - I binged listened to this on a 13-hour drive from Ohio to Nebraska
Episode 33: Made in America (Seeing White, Part 3) -A podcast on the origins of chattel slavery in what would become the United States
RetroPod - awesome podcasts about historical things from WaPo!


Lectures In History - A great series put out by CSPAN where you can watch college history professors give lectures.  Also available in podcasts. Sucked me in on a drive from Nebraska to Utah! 
Some favorites (I haven't listened to them all)
Colonial American Before the Revolution (really delves into the causes of independence)

The Erie Canal

YouTube Video