Barbed wire, still an essential tool in the livestock industry, is today a popular collector's item.
At three points in US history, six presidents (current or former) were alive at the same time. These points were: From March, 1861-January, 1862: Presidents Van Buren, Tyler, Fillmore, Pierce, Buchanan, and Lincoln were alive. January 1993-April 1994: Presidents Nixon, Ford, Carter, Reagan, Bush (the first) and Clinton were all around. January, 2001-June, 2004: Still living were Presidents Ford, Carter, Reagan, Bush (the first), Clinton, and Bush (the second). When either Trump or Clinton take office in January, 2017, he or she will join Carter, Bush I, Clinton, Bush II, and Obama as living presidents, making it a fourth time in history six presidents were alive.
Quick Answer. Republican President Ronald Reagan was the oldest acting U.S. president; he was 69 years old (just a few days shy of his 70th birthday) when he took office in 1981, and he served two consecutive terms, meaning he was in his 70s for the majority of his tenure as president.