Built in 1741, Faneuil Hall in Boston is, by most accounts, the literal birthplace of America as we know it. The hall, from which the surrounding tourist-centric neighborhood takes its name, was the site of some of most pivotal moments in American history — it’s where the Sons of Liberty rallied around the “no taxation without representation” doctrine and where Sam Adams and other orators urged Bostonians to join the cause of independence. The area is still home to some of the oldest bars and restaurants in the country, including the Bell in Hand, established in 1795, and the 1826 Union Oyster House. In 2007, a different icon of American history, the Hard Rock Cafe, opened its doors nearby.On a recent Saturday evening, the patio outside the Hard Rock is lively with sun-beaten dads and shopping-bag-toting moms, freedom-drunk suburban teens and European tourists dining al fresco while a piano player runs through Billy Joel’s “New York State of Mind.” You’d be hard-pressed to find a more succinct tableau of contemporary Americana, but I am here looking for something else: a taste of the world. There are almost 200 Hard Rock Cafes in 59 countries. Although there’s a certain homogeneity to the menus, chefs at each location are given latitude to design hamburgers that reflect the unique characteristics of their area. Boston’s, for example, comes topped with lobster. Suprising? Hardly. The chain recently winnowed down 150 such burgers from around the globe to compile its limited-offering World Burger Tour menu, four of which are on offer now in the heart of the Cradle of Liberty. I am here to eat them all.