I was looking at some recent additions to the site and came across the US Navy pages for the 1913-1918 period. Nicely done. I have to mention the designs of the officer caps look a little familiar to me!
I don't know how in-depth the page needs to go, but I thought I'd mention one change that came along in late 1918 that is not often mentioned in the reference books. The blue service collar insignia were changed from this
to this
by Change No. 26 to the Uniform Regulations, dated Nov. 30 1918. Some officers wore their stars "upside down," as in this photo of William S. Benson, but the regulations specified one ray point up.
I would also mention the white shoulder straps with metal insignia listed here as "1913-1917" were authorized less than a year before the standard shoulder boards were brought back in July 1913. It is doubtful that they were ever widely worn.
Best regards,
Justin