In cooler regions, wheat was often the crop of choice when lands were newly settled, leading to a "wheat frontier" that moved westward over the course of years.
Di daerah yang lebih dingin, gandum sering menjadi tanaman pilihan ketika tanah baru saja dihuni, yang mengarah ke "perbatasan gandum" yang bergerak ke arah barat selama bertahun-tahun.