TOWNS
The O'Brien County Courthouse is located at 155 South Hayes Avenue, Primghar, IA 51245. Phone: 712-957-3255.
In 1850 the Iowa State Legislature appointed a committee for the purpose of giving names to its counties. The committee named some of the counties after the patriots of Ireland and hence O'Brien County was named after William Smith O'Brien, a leader of the Irish revolt in 1848. [†]
O'Brien County is uniform in shape, a perfect square, 24 miles each way. 16 townships of six square miles. Two rivers, the Little Sioux and Ocheydan. Smaller streams are Mill Creek, Waterman Creek and branches of the Floyd River.
O'Brien County was without a settler until the spring of 1856 when Hannibal H. Waterman, his wife Hannah H. Waterman and their child, Emily landed in O'Brien County with two yoke of oxen and a small amount of household goods. Mr. Waterman exercised his right as a squatter by filing a claim at the government land office in Sioux City and settled on what became known as The Waterman Place, the northeast one-fourth of Section 26 of what is now Waterman Township. It is an area five miles northwest of Peterson. The next year the first white child born in O'Brien County was the Waterman's daughter, Anna, born May 30, 1857. In the next few years, there was something of a rush of settlement into O'Brien County. In fact, the first school in O'Brien County was taught by Mrs. Waterman in 1860 and the first school building was built in 1869 in Grant Township (northeast of Sutherland.) It was built from bricks made from the local clay ground.
† www.obriencounty.com/community/history, accessed May, 2025.