You will have to be at least a cousin to request a copy since it was prior to 1940. You can find the forms here, http://www.kdheks.gov/vital/marriage.html.
There is a $12 fee and they will do a 5 year search. The year you give and 2 yrs either side.

Deb
Surnames;Delaplain, Leavitt, Perkins, Caldwell, Covault.
Allen Co.