As a center of the regional economy, Kaskaskia was the capital of Illinois Territory from 1809 until Illinois became a state in 1818. Zaskaskia continued as the state capital until 1819. Its peak population was about 7,000 before the capital moved in 1819 to Vandalia. Although introduction of steamboats on the Mississippi River helped the economies of river towns in the 19th century, their use also had devastating environmental effects. Loss of trees (Deforestation) along the river banks was caused by steamboat crews' cutting trees to feed the engine fires. River banks became unstable and collapsed into the water.