Well my dad has finally scanned in all the slides his parents took when he was young. There are slightly over 1000 slides.
There are pictures of Doppenbergs in California, Langstraats in Washington, Leusinks in Wisconsin, Doppenberg and Langstraat family reunions and other get-to-gathers. Pictures of his uncles, aunts, cousins and others. And of course pictures of their kids and some trips they took.
Please take a look at them. Here is the link:
http://www.langstraat.com/pete-liz-langstraat-slides/
If you recognize someone in the pictures, please pass this link along to them as well. Enjoy and thanks!