Photo History - Are There Photos of My Ancestors?

I've decided to do a little research about the origins of photography and when it became a household must. The first thing that comes to my mind is Eastman Kodak.  Am I on the right track?  I am hoping to determine, for my own reference, the time frame and likelihood of finding photos of my ancestors.

Creating memories through photos is nothing new but prior to 1890, photos were not so commonplace.  I have found many photos starting in the 1890's of my ancestors.  When I say many, I mean that I have at least a photo of each direct line family member on my mother's side going back four generations. 

While I may be missing a photo of Lizzie Strehlow (Elizabeth Borchers), I am confident that someday I will acquire a photo of my great grandfather's oldest sister.  She's the only one missing from the family portrait that I have below.  I am certain it is because she was already married and out of the house by then.

Borchers circa 1898-1900

Below, I have a few dates that are key to Eastman Kodak's photography and the popularization of the camera:

1.  1888 - The first model Kodak camera appeared.
2.  Early 1890s - The first folding Kodak cameras were introduced.
3.  1895 - The first pocket camera, the $5 Pocket Kodak, was introduced.
4.  1897 - The first folding pocket camera was introduced.
5.  1900 - The Brownie camera was introduced for mass marketing of photography.

I was able to get the above information from Wikipedia.  What this demonstrates is that photography hit its stride by 1900 and, just prior, in the 1890s photography started to enter popular culture with access for most anyone, affordability considered.

Prior to 1890, photography was not necessarily for the masses.  Professional photographers took portraits and photographs of people.  This leads me to another timeline of key dates:

1.  1725 - Basic "photograph" type images using stencils, sunlight, and chemical solution. (That does not sound like much of a photograph!)
2.  1800 - Silhouette type photos were produced.
3.  1816 - Negative photographs on paper were invented.
4.  1839 - Photographs on silver-plated sheets of copper are invented.  Photography enters the public eye.
5.  Mid-1800s - Portrait photography becomes more commonplace in popular culture.

My quick research online turned up some specific and not so specific details of photo history.  I am satisfied with what I found.   What it tells me is that the likelihood of finding photos of my ancestors prior to 1850 will be "null and void".  Finding photos prior to 1890 will be less likely, too.  Yet, I have a few that have been shared with me.

Ellen Maxwell and Thomas M. McLaughlin, circa 1870

I love photos and they can be so telling.  "A picture is worth a thousand words." - Chinese Proverb