In 1849 the first family located in Greene County. Truman and May Davis moved up the Raccoon River valley from Adel and built a cabin for their six children. Shortly thereafter, several farm families followed up the river. They purchased land from the federal government for $1.25 per acre.
A city in Dubuque County had already registered to name their community “Jefferson”, therefore the Post Office Department rejected the new community. Jefferson became the county seat for Greene County in 1854 when the Dubuque community died out.
By 1856 fifteen more families arrived. A dry goods store, several craft shops, and a courthouse were built for the new county seat. In 1857, the first school met in the courthouse, and the weekly mail was established from Adel. In 1859, the first Greene County pork went to the U.S. markets and the first printing press and newspaper started.
Greene County had a population of 1,400 in 1861. When the Civil War began 150 men from the county were sent to fight for the Union. When the South surrendered in 1866, the Union Pacific Railroad helped ship goods and people to Jefferson. Greene County’s population had grown to 12,727 and Jefferson’s population was 1,444 by 1880.
By 1886, Jefferson had two banks, two newspapers, eight lawyers, five physicians, two dentists, eight teachers, five restaurants, two meat markets, seven groceries, three hardware stores, four general stores, two feed stores, two clothing stores, two shoe and boot stores, two blacksmiths, three drugstores, two furniture stores, two jewelers, two barbers, two hotels, tow opera houses, a creamery, a saloon, a post office, a bookstore, a secondhand store, a post office, a bookstore, a secondhand store, a billiard parlor, an abstracts and loan office, a photographer, several painters, a sewing machine shop and an organ shop.
Greene County’s population peaked at 17,820 residents in 1900.