Some autograph material of most Presidents for this reason is still priced within the reach of the average budget. Starting with President Kennedy, the Presidential picture clouds. The historical tides generated by America's wars have attracted many collectors. The Civil War has long had the most followers. Paperwork was very big during the Civil War and except for top Confederate material, the supply is excellent.
Some collectors stick to one side or the other, but most are fairly neutral.
For the American Revolution, being deeper in our history with far fewer and less literate participants than the Civil War, material is much scarcer and higher in price. Routine war documents still abound, however, and autographs of some major figures such as Robert Morris and Benjamin Lincoln are common. Speaking of Morris, the Signers of the Declaration of Independence remain collecting classics, though with several real rarities to contend with, completing a set is not the aim of most of the Signer collectors. Growing, too, is interest in the wars of the 20th century. The conflicts in American history just naturally draw greater interest than the more peaceable periods.