Various state historical societies video tape their events. You can look for their youtube channels. My local societies is here: https://www.youtube.com/@oregonhistory/videos

There's similar ones for groups focused on more defined areas, like Gilder Lehrman has a channel for US Civil War stuff. https://www.youtube.com/@gilderlehrman

Gilder Lehrman recently had an event at Yale specifically for teachers. I they had a big wig there too. I can't remember if it was Eric Foner or David Blight

Also, CSPAN's author talks are fun. Or you can just search for authors and books you like to find talks by those people. Lots of bookstores started putting up their author events during the pandemic.