Who were the oldest and youngest signers of the Declaration of Independence?

The youngest signer of the Declaration of Independence was Edward Rutledge of Southern Carolina. He was 26. He was also initially opposed to independence, but signed the Declaration for the sake of unanimity.

The oldest signer was Benjamin Franklin, who was 70 at the time. At the signing, Franklin famously said "We must all hang together, or, most assuredly, we shall all hang separately."