Who came up with the idea of Disney characters signing autographs at Disneyland?

[DodgerGirl]

I enjoy discovering and learning facts about Disneyland and I would like to know who came up with the idea for the Disney characters to sign autographs during meet and greets? Because even though the characters aren't real the autographs during meet and greets are so unique and cool. When Walt Disney created Disneyland did he decide to make the character meet and greets like celebrity autograph sessions and did Walt get inspiration from seeing celebrity meet and greets and decided to do the same for Disneyland? Also which was the first ever character meet and greet and autograph session at Disneyland in 1955? I wonder if the vintage Disneyland character autographs are worth anything today