When U.S. President Barack Obama arrives in Japan on Thursday, as part of week-long trip to Asia, he will be on his way to becoming the first U.S. President to visit the city of Hiroshima, the site of the world’s first atomic attack in 1945. The emotionally charged event will build on the precedent set by President Gerald Ford’s visit to the East Asian country in the 1974, when he became the first U.S.