Development of the growing city continued in the early 20th century. The first high school was erected in 1905, across from the present-day First Baptist Church. The post office in Itta Bena was opened in 1918. The white minority dominated politics and the economy, as the state legislature essentially disenfranchised blacks by the constitution of 1890. Working as sharecroppers and tenant farmers, they had difficulty getting ahead in the agricultural economy. During the 20th century, many left the county for work in industrial cities of the north and midwest, in the Great Migration.