The Aro Expedition, which was part of a larger military plan to quell anti-colonial sentiment in the region, took place in the area of Aba during 1901 and 1902. During this military action, the British easily beat the native Aro people with an unknown number (presumed to be heavy) of casualties. In 1901, the British founded a military post in Aba and in 1915, a railroad was constructed to link it to Port Harcourt, which transported agricultural goods such as palm oil and palm kernels. In 1929 Aba was the site of a revolt by Igbo women, historically known as "The Aba Women's Riot", a protest of the colonial taxation policy. The riot started first as a peaceful protest against the initial census of women in the region, and subsequent assumed taxation of the women based upon rumour. The protests spread throughout the palm oil belt, but remained peaceful until a pregnant woman was knocked over during a "scuffle", and the lady losing her child. The news of this "act of abomination" spread rapidly and violent reactions ensued. After more deaths, some accidental, some not, occurred, a mass of 10,000 women marched on Aba. Sources dispute the numbers of dead, with 55 to over 100 being reported. By the 1930s, Aba was becoming a large urban community with an established industrial complex.