The thing is that in the United States, unlike in Japan, the states are not obliged to report their oldest living residents; there is no such tradition present there. In other words, many extremely long-lived individuals may remain invisible to the academic and/or public attention. As if it was not enough, unless there is a public obituary present, the deaths are reported with a statutory delay. All in all, the USA has a larger supercentenarian population than it would seem on the first glimpse. Note the newly emerged case of 114-year old Mrs. Ophelia Burks who may have been the oldest living American following the death of Delphine Gibson.