Aba is a city and a big trading center in Abia State, southern Nigeria, located on the Aba River. Aba was established by the Igbo People of Nigeria as a market town and then later a military post was placed there by the British colonial administration in 1901. The city became a collecting point for agricultural products following the British made railway running through it to Port Harcourt. Aba is a major urban settlement and commercial center in a region that is surrounded by small villages and towns. The indigenous people of Aba are the Ngwa. Aba is well known for its craftsmen. As of 2004 Aba had an estimated population of 1,020,900.