Paul Manns Chicago IL/Washington DC

Hi,

My name is Victoria Manns. I am in search of my grandfather (possibly deceased) and decendants. My grandfather (I believe is Paul Manns) lived in DC, had three sons with a woman named Janice Cooper. Mervin (my father), Paul, and Donald. If he is still living he could be well into his 80's. Additionally, I was told that he had a lot of siblings.
My grandfather's whereabouts were last known to be of Chicago IL.
If there is anyone out there that may have more information please respond to this post.
Thanks,
Victoria