The first European settlers of Appalachia, a mainly mountainous region of the eastern United States, arrived in the 1730s and were mostly of Scotch-Irish or German origin. Until recently travel in or across the region has often been difficult and many smaller communities have been physically remote from centres of population. The isolated character of the entire area has, however, been greatly overstated. Because of its varied history, its large expanse, and its loose borders, Appalachia represents neither a distinct nor a unified speech region. Several sub-regional varieties were the result of settlement by different groups. The broadest geographical definition of the region is from central New York southwest to northeastern Mississippi, with a population of 23 million.