a string of approximately 20-30 lights moving slowly in a northerly direction

I stepped out onto my driveway at 5:40 PM and looked up in the night sky and saw towards the south what I first thought was a shooting star or a plane/ satellite breaking up.
I continued to watch and realized the string of lights were not dissipating as you would expect with a meteor breaking up. Instead the string of lights continued to move in a northerly direction, eventually traveling nearly directly above me.
The lights all appeared to be the same size but were spaced at irregular intervals and all were traveling at the same speed as if they were either flying in unison or were part of a single craft.
They emitted no sound and were moving much slower than a regular aircraft.
It was hard to gage the size or distance as I was looking up into darkness and had no other visual reference points. All the lights were the same color, a whitish glow.
I tried filming with my iPhone but nothing shows up on the recordings. I did snap two photos. The lights passed over me, again moving at a constant speed in a northerly direction. They eventually faded from view, faster than I would have expected as they were so bright, almost like they disappeared in a fog.
I would estimate the whole sighting lasted three minutes and the distance the lights traveled from the time I saw them to when they disappeared to be approximately 5-10 miles as the crow flies.