When was electronic TV first available to public in USA?

[Sandy G]

Yeah, I remember seeing when I was a kid, a prewar pic of a rather uneasy looking young woman sitting & trying to balance a 14" & a 20" Dumont CRTs on their nether ends...They looked kinda like huge 7JP4s, or the biggest spotlight bulbs you ever saw in your whole, entire life...Maybe they told her how dangerous they were if she busted 'em or something, I dunno...But she looked like she was NOT a Happy Camper over the deal...