I grew up in Dallas County, but now live on the eastern side of Iowa.

Googling for Iowa Orphanages, I see this page: http://tiny.cc/S6afE which gives the name of an orphanage in Des Moines. Googling that name leads to this book segment, which appears to have been written about 1910: http://tiny.cc/MQIFZ

Googling on "Iowa Educational Aid Association" doesn't give anything more. But I'd say that the Iowa Children's Home Society is a good bet. They were still around as late as 1967 in Des Moines (http://tiny.cc/0GgnC), but I don't know what happened to them after that. IF the children were adopted locally, there MAY be record in the county probate files. I've never been successful in finding this, myself, but I've heard it can happen! Good luck!