On a warm summer day in 1839, Charles Lamb and his wife decided to leave their home in Vermont. They packed their few belongings and, with their infant daugther, headed west to St Joseph, Michigan. After working on the St Joseph docks for a short while, Lamb purchased a canoe and traveled up the Paw Paw River into what is now Hagar Township. The Lambs built a log cabin and the young family became the first permanent settlers.

After helping the Lambs move and build their cabin, Mathias Farnum felt the attraction of the dense woods and beauty of the area. In the fall of 1839, he filed a claim on 160 acres and became the second permanent settler. More people soon followed and the decision was made to form a separate township. On March 25, 1846, the community was officially incorporated as Hagar Township.

Hagar Township is located in Northern Berrien County along the shoreline of Lake Michigan. The township is not as densely populated as some of the other lakeshore towns and the cost of living in Hagar Township is generally lower. The township comprises mainly grain and fruit farmers. The community is beautifully located amidst dense woods and along sandy beaches. It is easily accessible from I-196 and M-63. Hagar Township is beautifully located, very quiet, and within proximity of several shopping and recreational areas in Berrien County and neighboring Van Buren County. The township has its own small shopping area, and a small community called Riverside forms the heart of Hagar Township. These characteristics make the community a welcome place to live.

According to the 1990 census, the number of dwellings in Hagar Township is 630. Of these, 471 are owner occupied with the remainding 159 renter occupied. The median home value is $50,100. In 1999, the total work force was 2,125 with 2,025 of these fully employed.