WEEHAWKEN, N.J. — Beside a mighty river, tucked away in the shadow of a towering ribbon of asphalt that leads drivers into the Lincoln Tunnel and Manhattan beyond, sits a plot of land notable because of a two-century-old event that, for most Americans, is largely forgotten.

Here, during an 1804 duel, Aaron Burr shot and killed the guy whose face now decorates your $10 bills — Alexander Hamilton, the former Treasury Secretary. Burr was Thomas Jefferson's vice president at the time, and his action remains the highest-profile act ever committed by a sitting v.p. short of actually becoming president.

It's as if Dick Cheney had gunned down an armed Madeleine Albright in the parking lot of the Fairfax Costco. Yet when the country's No. 2 guy killed a rival Founding Father on the shores of the Hudson River and was charged with murder, he still ended up as mere historical footnote.

Which is precisely the point. Such has been, and is, the lot of the American vice president — sidekick, runner-up, constitutional escape hatch, perennial pretender to the throne in a country that doesn't have one.

"I'm here," he has often seemed to say to no one in particular.

"What is it exactly that the v.p. does every day?" Sarah Palin wondered rhetorically in July after being asked if she might be gunning for the job.

She was making a point. The vice presidency has long been an odd beast that no one is quite certain how to pet. It's a position that has been largely meaningless until, in the most dire of circumstances, it suddenly isn't.

"He's superfluous — until he's president," says Jeremy Lott, author of "The Warm Bucket Brigade: The Story of the American Vice Presidency."

Indeed, despite Al Gore's high profile and Cheney's behind-the-scenes ministrations, the job for which Palin and Joe Biden are vying remains a cipher. By intent or neglect, it was built that way from the beginning. And its occupants have felt the effects.

After William McKinley's assassination in 1901, Republicans were terrified that his raucous, brash vice president would lead the country to ruin. Theodore Roosevelt, we now know, didn't. "His Accidency" John Tyler, Andrew Johnson and Chester Arthur didn't distinguish themselves as well when their bosses expired in office. Harry Truman did, though it took America a while to recognize it.

Whether or not they rose to the occasion, however, at least those guys are remembered.