Unfortunately there are still loads of episodes missing from the Hartnell/Troughton era, because the BBC foolishly wiped them. Every so often a duplicate turns up in someone's attic, but much of the classics from that era it seems are gone for good (The Web of Fear for instance). In some cases, they have the audio from the episodes, and have animated them (in monochrome, trying to keep to the creaky, low-budget style of the original).

I have a vast collection of Doctor Who DVDs - everything from the post 2005 relaunch, and most of the very best stories from the classic era (the afore-mentioned missing episodes notwithstanding). They are almost all available on DVD. If physical media isn't your thing (I'm a strictly old-school physical media person) then I think BBC iPlayer has all the post 2005 episodes up, and you can also get all the classic era Doctor Who on Brit Box (except the afore-mentioned missing episodes). However, since you are based in the US (I assume) it might not be that straightforward. But there's bound to be a way, I imagine. Good luck tracking them all down. :)