Bay Shore has a railroad station of the Long Island Rail Road, which serves both commuters and vacationers as a major gateway to Fire Island.
The oldest structure in Bay Shore is Sagtikos Manor. The earliest part of the sprawling house was built in 1692 by New York City's first native born mayor, Stephanus Van Cortlandt. The manor functioned for a time during the American Revolution as local headquarters for British forces. George Washington used it as a stopover during a 1790 tour of Long Island.
Like nearby Babylon Village, Bay Shore became renowned in the late 19th century for its shopping district and resorts. With its convenient and appealing location along the Great South Bay and access to Fire Island, Bay Shore became popular with affluent New Yorkers looking to escape the city. It was a tourist spot on weekends and during the summer, in large part because the newly built Long Island Railroad enabled easy access from Manhattan and Brooklyn. It eventually evolved into a suburb of New York City.
According to the Suffolk County Film Commission, the Biograph movie studios started filming in 1902 in Bay Shore. The film cameras needed the bright light reflected by the ocean to properly expose the film. The Keystone Kops had their start in Bay Shore, as did the early "Our Gang" shows.
Population increased significantly after World War II: From the mid-1950s through mid-1960s, a wide variety of housing developments were constructed on land that had previously been farms and unused woodlands. Those developments were settled largely by working and middle class first time home buyers who were following a typical pattern of "urban flight" from New York City. Many of those new residents were of Irish or Italian extraction.
Despite strains on the sense of community and historical continuity brought on by sudden and substantial growth, the town remained well-regarded. Main Street continued to be a popular shopping destination for people from all over the region.
Unfortunately, Bay Shore suffered a decline beginning in the late 1960s. The hamlet was never incorporated. Without a local government, long-term residents were unable to make local decisions that were instead left to the Town of Islip and Suffolk County. Density and demographics shifted in some older neighborhoods when rezoning permitted businesses, rental properties and multi-family dwellings where previously only single-family houses had been allowed. Many Main Street storefronts became dilapidated or vacant. The luxury Cortland Hotel along with other historical sites was closed, the parks were left unkempt, and disgusted prominent residents relocated. A contributing factor to blight in Bay Shore's downtown shopping district may have been construction just two miles away of the large South Shore Mall (currently Westfield Shopping Center of Bay Shore). Additionally, deinstitutionalisation led former residents of the nearby Pilgrim State Hospital to be hastily placed in rental housing and former hotels in the town's center, often without sufficient professional support.
Facilities and restaurants on the Great South Bay waterfront fared better, partly because it is an embarkation point for ferries to villages on Fire Island that are not accessible by private car.
Several attempts were made at suburban regeneration from the 1970s through the 1990s. A large number of upscale town houses and condominiums were built in gated communities on the grounds of old estates. A planned aquarium was never constructed. However, a former movie theater and one time opera house was rebuilt and expanded into an attractive YMCA. Redeveloping Main Street continues to be a focal point; efforts include new sidewalks, antique-style streetlights, new landscaping and parks. Main Street is again becoming a destination; there are many attractive and well-rated new restaurants, clothing boutiques and other stores and offices.
The Bay Shore Public High School and Bay Shore-Brightwaters Public Libray (in adjacent Brightwaters, New York) have recently undergone extensive renovation and expansion, with exceptional attention to architectural detail.
Awixa Avenue is known for large historic homes, like the W.H. Wray House (which is reputedly haunted by the ghost of Adeline Wray), the Awixa Castle, the Hulse House (which has fallen into disrepair), and the Guastavino Tile House.
According to the United States Census Bureau, the hamlet has a total area of 6.1 square miles (15.8 km²).13.6 km² (5.3 mi²) of it is land and 2.1 km² (0.8 mi²) of it (13.30%) is water.
There were 8,194 households out of which 33.0% had children under the age of 18 living with them, 46.8% were married couples living together, 15.2% had a female householder with no husband present, and 32.5% were non-families. 25.9% of all households were made up of individuals and 10.5% had someone living alone who was 65 years of age or older. The average household size was 2.1 and the average family size was 3.10.
In the hamlet, the population was spread out with 25.9% under the age of 18, 8.9% from 18 to 24, 32.5% from 25 to 44, 21.3% from 45 to 64, and 11.4% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 96.0 males. For every 100 females age 18 and over, there were 93.0 males.
The median income for a household in the hamlet was $50,155, and the median income for a family was $69,046. Males had a median income of $49,878 versus $39,851 for females. The per capita income for the hamlet was $29,437. About 8.1% of families and 12.1% of the population were below the poverty line, including 17.1% of those under age 18 and 8.1% of those age 65 or over.
Their mascot is the Marauder.