The city began as Ageo-juku, a post town on the Nakasendō during the Edo period. Ageo's rail station opened in 1883. In 1889, Ageo-juku merged with the villages of Ageo, Ageoshimo, Kashiwaza, Kasugayatsu and Yatsu to form the new town of Ageo. The two towns of Hirakata and Haraichi and the three villages of Kamihira, Ōishi and Ōya merged with the town of Ageo in 1955, and Ageo obtained city status on July 15, 1958, with a population of more than 37,000. In the second half of the 20th century, metallurgy and automobile factories were constructed. Housing increased during that period, as it did in the suburbs of Tokyo and in cities of southern Saitama.