That commission, signed in 1703 by the King and his minister Jérôme Phélypeaux comte de Pontchartrain, was significant in that it recognized the strategic importance of La Balize. Despite the vulnerability of the low-lying site to hurricanes, the French and later the Spanish needed to control the mouth of the Mississippi and have a place where pilots could meet the ships. They always rebuilt. The complicated conditions on the Mississippi River required ships to have river pilots to help them navigate the bar, with its changing currents, mud and sandbars, and avoid going aground. After the Americans took control of the territory by the Louisiana Purchase in 1803, they sometimes called the village Pilotsville. With the advent of steam tugboats in the 19th century, the pilots had more power to maneuver oceangoing ships in the river. Not only did hurricanes destroy the settlements, but engineers started working early to try to improve entry at the river mouth. In 1726 French engineers dragged an iron harrow through sandbanks to make it easier for ships to pass the bar. Other elements which pilots and captains had to deal with at the mouth of the Mississippi were changing passages. The main ship passage changed four times before 1888. In 1750 the main passage was at the Northeast Pass (part of "Pass á Loutre"), then in succession it was at Southeast Pass (also in Pass á Loutre), Southwest Pass, and South Pass. The main ship passage is again in the Southwest Pass. Historical records for La Balize documented the long struggle of the French, Spanish and Americans to maintain this critical site at the delta front:   The hurricanes of 1860 persuaded the pilots and their families to rebuild further upriver, which they did about five miles (8 km) away, on the east bank of the Mississippi. The new settlement was named Pilottown. At its peak of population in the 19th century, it had about 800 residents. A school for children operated into the 20th century. Today the pilots usually stay there only temporarily for work shifts. Little of La Balize remains today. In the early 20th century, only a rusted iron tomb marking the site remained. Travelers found the Mississippi delta an astonishing area. In her "Domestic Manners of the Americans" (1833), Fanny Trollope captured her first perceptions as her ship entered the area of the river: Large flights of pelicans were seen standing upon the long masses of mud which rose above the surface of the waters, and a pilot came to guide us over the bar, long before any other indication of land was visible.