I have been involved in the sports side of autograph collecting for a number of years, but recently I've started exploring and researching presidential and other historical political autographs.

If anyone can suggest knowledgeable and reputable dealers in presidential and historical autographs as well as auction houses that offer and specialize in the area.

The only auction house that I am aware of is RR Auction so any suggestions, input or other tidbits of information would be greatly appreciated.