The peaceful tribe of Quinnipiacs were the first residents of the land that is now Hamden, they had great regard awe and veneration for the Blue Hills Sleeping Giant Mountain. [1]Hamden was purchased by William Christopher Reilly and the Reverend John Davenport in 1638 from the local Quinnipiac Native American tribe.

It was settled by Puritans as part of the town of New Haven. It remained a part of New Haven until 1786 when 1,400 local residents incorporated the area as a separate town, naming it after the English statesman John Hampden.Largely developed as a nodal collection of village-like settlements (which remain distinct today), including Mount Carmel (home to Quinnipiac University), Whitneyville, Spring Glen, West Woods, and Highwood, Hamden has a long-standing industrial history.

In 1798, four years after Eli Whitney began manufacturing the cotton gin in New Haven, he made arms for the U.S. government at a mill site in Hamden, where a waterfall provided a good source of power. At that site, Whitney introduced the modern era of mass production with the concept of interchangeable parts. The major thoroughfare through Hamden is named Whitney Avenue in honor of Eli Whitney, and it runs past Whitney's old factory, now the Eli Whitney Museum. Whitney constructed stone houses for his employees in the nearby area, which is still referred to as Whitneyville; this is believed to be the first example of employer-provided homes in U.S.

history. In 1806, the dam that Eli Whitney built at the mill site was enlarged to create a reservoir, Lake Whitney. The first truss bridge in the United States was erected nearby over the Mill River in Whitneyville in 1823, but has since been replaced. The Farmington Canal, which ships traveled from New Haven northward, passed through Hamden between 1825 and 1848 until it was supplanted by railroad travel.

The canal right-of-way has become, in recent years, a popular walking and bicycling trail, passing by some of the well-preserved locks of the canal, as well as some of Hamden's oldest sites. Before its use as a walking and bicycling trail, many local residents rode their motocross bikes on the Farmington Canal. During the 19th and early 20th centuries, Hamden received a steady influx of immigrants, most notably from Italy and Ireland.

To this day, a large part of Greater New Haven's Italian-American community resides in Hamden. During the post-war period, Hamden underwent significant suburban development. Much of the southern section of town is urbanized and is difficult to distinguish from neighboring New Haven. The northern section of town, however, retains a more rural character, and has the distinct neighborhood of Mount Carmel.

This area of town is the location of the unique Sleeping Giant hill formation that is the source of the town's nickname.