You are exactly right, all children wore dresses until out of diapers.  Please provide a little more about the book and I will try and find it.
Exact words in the title (don't need all) date of pub or anything else you remember.  

Charles D. Neel
Vice President

Red River Archaeology, LLC
10100 North Central Expressway, Suite 160
Dallas, TX 75231
Office: 214-741-2252
Cell: 214-478-4424

________________________________________
From: HISTORICAL ARCHAEOLOGY [[log in to unmask]] on behalf of Susan Walter [[log in to unmask]]
Sent: Friday, July 03, 2015 2:16 PM
To: [log in to unmask]
Subject: skirts on little boys

July 3, 2015
Hi All,

I have a project luckily augmented with the family’s photos.  My male subject was born in 1881, and the first photos of him depict him wearing little kilts / dresses.

Has anyone got good references about the gender neutral dresses for young children that was common up even until the 1930s?  I’m not finding much written at all, except that that both boys & girls wore the same type of garments up to about the age of 5.

I’m positing these open bottomed garments were helpful for diaper changing...

I used to have a book – it was called something like When Boys Wore Dresses – and it showed a young boy (the author’s son) on the cover in a short dress.  I cannot find the darned thing, either here in my office nor trolling around amazon.  Anyone recognize that?  Or know of other references?

I appreciate any help!
S. Walter