If you want fascinating together with superb narration, both
The World at War :
https://www.imdb.com/title/tt0071075/ and
The Civil War :
https://www.imdb.com/title/tt0098769/
are unequalled in their respected fields.
I’ll second Ken Burns “The Civil War”, I’ve seen it from start to finish a couple of times, and if I notice there’s an episode on as I’m channel surfing, I’ll watch that one again.
The episode where the 75th anniversary of the Battle of Gettysburg in 1938 was shown would make a grown man cry.
Old guys of 90 odd to 100, dressed in blue or grey, medals on display, shook hands across the low stone wall that was the target for Confederate General George Pickett’s disastrous charge on the last day of the battle, Pickett suffered 50% casualties.
There are some fascinating snippets on there, e.g. the Union Major-General Joseph Hooker allowed his men to fraternise freely with the prostitutes that followed his command.
They became known as Hooker’s Division, and from there we get the word ‘hooker.’
After General John Pemberton surrendered Vicksburg MS to General Grant on July 4th 1863, Independence Day was not celebrated in Vicksburg for 80 years.
I tend to look at recommended lists from the likes of Guardian and start from there.