I believe that these three are brothers. In letters that I have that were send to Oliver Abraham VS. One states "Dear Brother Oliver Van Sickle" and is signed "Charles Van Sickle" It is dated May 4, 1870
In some other letters I have found references to Johnson Van Sickle. I have some one that gave me some info on Johnson, but would like to find a connection to go backwards. and find out more about all three.