1802 - The Town of Williamson is founded from land split from the Town of Sodus.
1808 - The first school in Williamson is built in Pultneyville, a one-room building with Mr. Morrison as the teacher.
1811 - Pultneyville becomes District One when a second school house is built in the Village of Williamson on East Main Street (Williamson becomes District Two); Mr. John Lambert is the teacher. The structure burns down at some point, but is immediately replaced by another that serves District Two until the mid-1850s (when it, too, burns down).
1850 - District Number Eleven opens in "Koetsville", at the north-east corner of Shepard and Stoney Lonesome Roads.
1853 - A state law authorized one or more common districts to form a "union free school district". This law permitted the new districts to establish "academic departments," or high schools.
1855 - A Cobblestone school building is constructed for District Two, located on the corner of East Main and present-day Locust Street
1876 - District Two is enlarged and a new, larger school building is built on Miller Street, on what is now the front lawn of the Middle School. D.D. Warne is the principal of this two-story structure, which has two classrooms on the first floor and the town's first auditorium on the second. Maple Avenue is created to provide access to the school. While the school serves primarily District Two children, children from some of the other 12 districts in Williamson attend as well (thanks to tuition paid by their respective districts).
1895 - The Williamson Union School is registered by the State of New York
1902 - The "academic department" of Williamson Union School is registered as a New York State High School.
1907 - The school is enlarged, doubling its size.
1914 - 1918 - Formation of central rural school districts was first authorized by a 1914 law. In 1917 the Legislature abolished all the thousands of common school districts and formed them into "township units." Across the state, school taxes shot up, taxpayers protested, and a year later the township system was abandoned.
1922 - District 2 overcrowding prompts additional space for teaching grades 1 – 5 to be rented in the Grange Hall.
1924 - Portable classroom building rented and placed on present-day Middle School tennis courts location.
1930 - On April 25 Williamson voters decide to “Centralize” its school system, creating Williamson Central School from 8 of the town’s 13 Districts (Pultneyville, East Williamson and Benton are opposed to centralization and decide to maintain their own District schools).
1931 - In June the WCS Class of 1931 holds its commencement exercises in the newly-completed school building (built at a cost of $375,000). The new school is dedicated on September 27 and officially opened. It has 600 students, a staff of 32 teachers and five buses.
1941 - Enrollment drops from 650 to 607 almost overnight due to World War II enlistments.
1947 - After four to five years of declining enrollment due to WWII enlistments, the student population sharply increases due to resumption of interrupted educations and the dissolution of the East Williamson District.
1948 - The Benton District dissolves as well, further swelling the student body.
1949 - Board of Education purchases land to the south-east of the school for future expansion.
1950 - Enrollment increases to 850. New wing added to school building comprising 6 classrooms and a cafeteria.
1954 - School District has over 1,000 students and a faculty of 51.
1956 - Primary school for grades K – 3 constructed on land purchased in 1949. Board of Cooperative Educational Services (BOCES) created.
1964 - The need for further expansion is recognized, but plans for a new high school building are complicated by the state’s “Master Plan” for education requirements that would mandate Williamson to combine with Marion.
1966 - Disregarding its own Master Plan, New York State approves financial aid for a Williamson-only high school. Construction begins.
1969 - The Williamson Senior High School is officially opened on October 13.
1970 - Student enrollment reaches 1,792.