Hi Baily49 i think this a polemonium also known as jacobs ladder.

I agree.

Could be Jacob's ladder. I had one once which was blue & looked very much like that. Very pretty.

Polemonium caeruleum album and a real seed weed if you do not cut it down after flowering.

Didn't know there were white ones. I have a blue one which does indeed seed very prolifically.

I have a blue one and although it's quite large, it has never been a problem self-seed wise but I do cut it right back. I didn't know you could get white ones!! You learn something every day eh??!! lol

I have both blue and white. several varieties of the blue and the white one and also a lovely pale pink one. they are good self seeders, and in my borders thay are allowed to romp away.