By the mid-1820's, many settlers had obtained government land grants in the township, the majority of them from New York.
A meeting to organize the township was held in April 1827 at the home of Alvin Nye. When it came time to chose a name for the new township, Daniel Thurston, who presided over the meeting, said "I move we name the town in honor of the father of our country." The name Washington was enthusiastically accepted by the group. The township originally included what is today Washington and Bruce Townships. Bruce Township became a separate entity in 1833.
The first school was a log schoolhouse built in 1824 just south of the Washington Village with Miss Emeline Allen, younger sister of the early settlers William and John Allen, as the first teacher.
In the early days, there were circuit ministers who visited Washington Township, otherwise people had to travel to Utica for worship. The first organized church was the Methodist Church formed in 1823. Services were first held in homes, then in schoolhouses, and finally a building was erected in 1846 where the Methodist Church is today. The next church to appear in the township was the Washington Union Church which was organized in 1879. The church building still stands today across from the museum.
The township has historically been a productive farming community, with a strong emphasis on orchards. In 1850, Washington Township had 119 farms and by 1874 that number had grown to 196. Beginning in the 1950's, much of the farmland has been sold and converted to subdivisions. The current Township is 36 square miles: 26 Mile Road to 32 Mile Road and from Dequindre to Hayes (Powell) Roads.