dispatch to the King from Viceroy de Croix and visitador José de Gálvez, dated January 28, 1768. Gálvez sought to make a distinction between the Antigua ('old') area of established settlement and the Nueva ('new') unexplored areas to the north. At that time, almost the only explored and settled areas of the province were around the former Jesuit missions but, once exploration and settlement of the northern frontier began in earnest, the geographical designations ('upper') and ('lower') gained favor. The single province was divided in 1804, into Alta California province and Baja California province. By the time of the 1804 split, the Alta province had expanded to include coastal areas as far north as what is now the San Francisco Bay Area in the U.S. state of California. Expansion came through exploration and colonization expeditions led by Portolá (1769), his successor Pedro Fages (1770), Juan Bautista de Anza (1774–76), the Franciscan missionaries and others. Independent Mexico retained the division but demoted the former provinces to territories, due to populations too small for statehood. Department of Mexico In 1836, the designation Las Californias was revived, reuniting Alta and Baja California into a single departamento (department) as part of the conservative government reforms codified in the Siete Leyes (Seven Laws). The Seven Laws were repealed in 1847, during the Mexican–American War, and the split of the two Californias was restored. California briefly achieved independence after the Bear Flag Revolt but quickly came under the occupation of American forces. Following Mexico's defeat in the war, most of the former Alta California territory was ceded on 2 February 1848 to the United States, under the terms of the Treaty of Guadalupe Hidalgo. The new Mexico–United States border was established slightly to the north of the previous Alta-Baja border, and the terms and were no longer formally used. The areas in North America acquired by the U.S. were designated as unorganized "territory" under a military governor, pending re-establishment of civilian control and organization. California was the first section of the territory to achieve statehood, two years later. Geography The Baja California Peninsula is bordered on three sides by water, the Pacific Ocean (south and west) and Gulf of California (east); while Alta California had the Pacific Ocean on the west and deserts on the east. A northern boundary was established by the Adams–Onís Treaty of 1819. That boundary line remains the northern boundary of the