Memorial Day, also known as Decoration Day, was first observed in 1868 as a way to honor those who had died in the Civil War. Since expanded to include all who have died in U.S. wars, it was declared a national holiday in 1971. Communities across Long Island will mark the day with parades, services and other events.

Parade begins 10 a.m. at Frost Lane and Central Avenue, heads to Cedarhurst Memorial Plaza in the Andrew J. Parise Park, where a service will follow, 516-295-5770.

Begins 9 a.m., service followed by a ceremony of changing of the flags led by Boy Scout Troop 125, Commack United Methodist Church, 486 Townline Rd., commack.church, 631-499-7310.

United Veterans Organization ceremony, 10 a.m. to noon, Veterans Memorial Plaza Field 6, Eisenhower Park, 1899 Hempstead Tpke., 516-572-6565, 516-798-3710.

Assembly at 1:30 p.m., service at 2 p.m., Long Island National Cemetery, 2040 Wellwood Ave., 631-454-4949.

Military banner ceremony held at noon at Morgan Park, followed by wreath-laying ceremonies at the World War II Monument at the Morgan Park entrance, the Doughboy Monument at Glen Cove Public Library, the Ford Street Monument, the Elm Street Monument, Calvary African Methodist Episcopal Church Cemetery and St. Rocco’s Monument, glencoveny.gov, 516-676-2000.

A ceremony will be held at 12:30 p.m. at the Civil War Monument in Greenfield Cemetery, 650 Nassau Rd. Marching units then gather at 2:30 p.m. at Legion Square, Greenwich Street and Marvin Avenue, and parade to the cemetery, villageofhempstead.org, 516-478-6286.

Wreaths placed at the World War I, World War II, Korean War, Vietnam War, Women’s Military, Afghanistan and Iraqi Fallen Heroes monuments on the front lawn of Huntington Town Hall, 100 Main St., at 10 a.m. the Huntington Men’s Chorus performs, refreshments follow; after the ceremony, proceed to Village Green to place a wreath to honor the Huntington soldiers killed in Vietnam, 631-351-3012.

Begins at 8 a.m. at the Laurelton Boulevard Boardwalk, $45, longbeachny.gov/rec, 516-431-3890.

The U.S. Air Force Thunderbirds headline, 10 a.m. to 3 p.m., free admission, $10 parking, Jones Beach State Park, 2400 Ocean Pkwy., fourleafairshow.com, 631-321-3510.

Begins at 11:45 a.m. in Village Cemetery, parade steps off at noon at Cemetery Road along Main Street to Everett Drive, ending at Yaphank Fire Department, 631-924-3200.

Begins at 10 a.m. at the Village Triangle gazebo at Broadway and Park Avenue, 631-264-6000.

Steps off 9:55 a.m. at Foster Boulevard and Deer Park Avenue and heads to the memorial at Argyle Park Gazebo; service at the gazebo follows the parade; refreshments at American Legion Babylon Post 94, 22 Grove Place, 631-669-0094.

Assemble 9:15 a.m., parade begins at 9:55 a.m. at Grand Avenue across from North Baldwin Post Office and ends at Baldwin Veterans Memorial Plaza at Silver Lake Park, where a ceremony follows, 516-867-9873.

Assemble 11 a.m. at Middle Road and Connetquot Avenue, head east on Middle Road to the Bayport Memorial Park for a ceremony and wreath-laying service hosted by the Bayport Fire Department, 631-472-0641.

Veterans’ services held at 9:30 a.m. at Memorial Park on Union Boulevard in front of the train station; parade steps off at 11 a.m. at Lanier Lane and Main Street, then proceeds down Main Street to Brentwood Road and on to Oakwood Cemetery, 631-665-3526.

Ceremony on the steps of Village Hall at School Street at 12:30 p.m., followed at 1 p.m. with a parade that begins at Village Hall, 516-628-1439.

Begins 11 a.m. at Village Green and ends at Woodland Cemetery, ceremony held by VFW Post 8300, 631-286-0327.

Ceremony at 10:25 a.m. at John F. Kennedy Middle School, 500 Broadway, parade follows at 10:30 a.m. from the school and travels down Broadway, 516-707-3158.

Begins 10 a.m. at Hubal Street and Ocean Avenue, heads to the John Pearl Elementary School for a service at the Veterans Memorial (Church Street and Smithtown Avenue), then to the Bohemia Fire Department for a service and placing of wreaths, 631-589-2555.

Service starts at 8:30 a.m. at Brentwood Cemetery, Madison Avenue and Jackson Street, parade follows at 9 a.m. and concludes at Ross Memorial Park, sponsored by American Legion Post 1006, 631-273-4443.

Starts 9:30 a.m. at South Country and Beaver Dam roads, heads east to the Brookhaven Fire Department Memorial Park, where a ceremony follows, sponsored by Brookhaven Fire Department, 631-286-0282.

Starts 1 p.m. at Calverton National Cemetery, 210 Princeton Blvd., 631-727-5410.

Begins 9 a.m. at Lake Avenue and Main Street, heading east to Mount Pleasant Cemetery for a ceremony, sponsored by Veterans of Foreign Wars Victory Post 414, 631-878-4908.

Assembles at 10 a.m. at Centershore and Mill Dam roads, and ends at Park Circle, 631-351-3012.

Service held 9:30 a.m. at Queen of All Saints Cemetery, 115 Wheeler Rd., 631-234-8297.

Assembles 10 a.m. at Home Depot’s southeast parking lot, heads east on Jericho Turnpike to Veterans Memorial (Cmdr. Fred Amore Cannon Park) at Jericho Turnpike and Veterans Memorial Highway for a wreath-laying ceremony, hosted by Elwood-Commack VFW Post 9263, 631-780-4853.

Begins 10 a.m. at Copiague Middle School on Dixon Avenue and ends at the main firehouse, 320 Great Neck Rd., hosted by Copiague Fire Department, 631-464-4685.

Service at 9:30 a.m. at Holy Sepulchre Cemetery, 3442 Route 112, 631-732-3460.

Assemble at 9 a.m., begins 10 a.m. at East Meadow High School and ends at Town of Hempstead Veterans Memorial Park, eastmeadowvetshall.com, 516-978-5884.

Starts noon from Clay Pitts and Larkfield roads and heads to John Walsh Memorial Park, adjacent to Northport-East Northport Library, 631-351-3296.

Begins 9 a.m. at Walnut Avenue and Route 106, sponsored by the East Norwich Volunteer Fire Company, 516-398-3860.

Begins 10 a.m. at VFW Post 3350, 164 Main St., ends in front of the East Rockaway Village Hall, 376 Atlantic Ave., 516-887-8170.

Assemble at 9:30 a.m., parade begins 10 a.m. at Sewanhaka High School, ends at Elmont Memorial Library, services follow, sponsored by American Legion Post 1033, 516-351-5057.

Steps off 10 a.m. at Northside Elementary School, ends at Village Hall, a ceremony follows, farmingdalevillage.com, 516-249-0093.

Parade begins at 10 a.m. on Elizabeth Street, heads to Memorial Park for ceremonies at 11 a.m., sponsored by American Legion Post 334, 516-437-1295.

Starts at 10 a.m. at VFW Post 2718, 68 Lincoln Rd., heads to the gazebo and veterans memorial at the south end of Rath Park, sponsored by VFW Post 2718, 516-354-9393.

Assemble at Freeport High School, begins at 10 a.m. at South Brookside Avenue, ending at Freeport Memorial Library with a wreath-laying ceremony, hosted by American Legion Post 342, 516-377-2252.

Ceremony begins at 11 a.m. at Monument Park in front of First Presbyterian Church. Parade follows at noon starting at Cottage Row and Forest Ave., proceeding through downtown Glen Cove, 516-676-2000.

Assembles at the intersection of Willard Place and Glenwood Road (across from Our Savior Lutheran Church) at 8:30 a.m., and proceeds across Glen Cove Road ending at Memorial Park, where a brief service follows, hosted by Glenwood Landing American Legion Post 336, 516-676-7158.

Begins from Susquehanna Avenue at Middle Neck Road at 9:30 a.m., continues north on Middle Neck Road to the Village Green for a remembrance service and ceremony. Upon completion of the ceremonies, the parade proceeds to All Saints Church, 855 Middle Neck Rd., for a final salute.

Assembles at 9 a.m. at East Maple Road and Broadway, ends at Memorial Park, Broadway and Pulaski Road, hosted by Greenlawn Fire Department.

Begins at 9 a.m. at east Barclay Street and Route 107 heading south to Old Country Road, ending at Hicksville Middle School, a ceremony follows in the schools’ Memorial Garden, hosted by Hicksville American Legion Post 421, 516-287-3569.

Kicks off at noon at Gerard Street parking lot (by Post Office) heading down West Neck Road, east on 25A, ends on Stewart Avenue

Begins at 9 a.m. at R.J.O. Intermediate School, Old Dock Road and Church Street, ends at Veterans Plaza for flag ceremony, sponsored by Donald C. Munro American Legion Post 944, 631-269-4140.

Begins at 10 a.m. at American Legion Post 155, Church Street, heads to Raynor Beach County Park for a service at 11 a.m., sponsored by the AMVETS, VFW, American Legion Post 155, 631-588-1401.

Begins at 10 a.m. at Island Trees Middle School on Wantagh Avenue, to the Levittown Library, sponsored by American Legion Post 1711, 516-731-9114.

Begins at 10 a.m. at Breslau Cemetery, heads to the monument at Fireman’s Park for a ceremony with the Lindenhurst Fire Department at 11 a.m., then proceeds to Village Hall, 430 S. Wellwood Ave., for a ceremony at noon, 631-957-7500.

Kicks off at 2 p.m. in Great Neck on Northern Boulevard in front of the Manhasset-Lakeville Volunteer Fire Department Company 4 Firehouse, 718-279-3200, lndmemorialday.org.

Kicks off 9 a.m. on the corner of Forest Avenue and Ninth Street, wreaths are laid at four stops, and the American Legion Post 962’s rifle team fires a volley of shots saluting our fallen heroes; a ceremony at Locust Valley Primary School field follows the parade.

Parade begins at 10 a.m. along Plandome Road, from Plandome Court to Memorial Place, a memorial service takes place at Mary Jane Davies Park on Plandome Road after the parade.

Parade begins at 10 a.m. on Broadway and Commonwealth Avenue in Massapequa, ends at Brady Park on Lake Shore Drive, hosted by American Legion Post 1066 and the Sgt. Peter F. Colleran Post 7763, 516-798-0244.

Begins 9:30 a.m. at the lighthouse on Neighborhood Road and proceeds down Mastic Road, sponsored by American Legion Post 1533, 631-395-1981.

Memorial service at 10 a.m. honoring fallen firefighters and service members, at Melville Fire Department, 531 Sweet Hollow Rd., 631-423-2635.

Assemble at 8:45 a.m., parade at 9:30 a.m., Veterans Broadcast Plaza, between Merrick and Brooklyn avenues, to the veterans monument at Lee Avenue for 10:45 ceremony, 516-521-6989, merrickpost1282.org.

Parade begins at 11 a.m. at Union Street and Westbury Avenue, ends at Mineola Memorial Park, 516-747-5860.

Begins at 10 a.m. at the north end of Laurel Avenue, ends at Northport Harbor Village Park, hosted by Northport American Legion Post 694.

Assemble at 9:30 a.m., parade begins at 10:30 a.m. on South Street, breaks for waterside services, then proceeds to Town Hall West for a ceremony at the gazebo, 347-661-3548.

Service at 9 a.m. at Steven J. Crowley Memorial Park on Old Town Road. A second service will be held at 10 a.m. at Veterans Memorial Park, across from Village Hall, Port Jefferson Harbor, 631-473-9774.

Parade begins at 10 a.m. on Campus Drive, ends at Sousa Bandshell in Sunset Park for a service, sponsored by American Legion Post 509 and VFW Post 1819, 516-860-6991.

Begins at 11 a.m. at VFW Post Rocky Point, 109 King Rd., 631-873-8272.

Begins at 10 a.m., Field 2, North Centre and North Village avenues, ends at Rockville Centre Recreation Center, memorial service to follow, sponsored by the American Legion Post 303, 516-678-9212.

Steps off from Handsome Avenue and Main Street at 9 a.m., a service follows parade in Sparrow Park and concludes with a memorial service at the Sayville Fire Department, 107 N. Main St., 631-589-0189.

Begins at 9:30 a.m. on Merrick Road and proceeds north on Washington Avenue, ends at the Four Chaplains Monument in front of the Seaford Middle School, where a memorial service follows.

Begins at noon at Main Street and Singer Lane, ends at Town Hall, ceremony follows, hosted by Smithtown Fire Department, 631-360-7620.

Sound Beach Civic Association sponsors a memorial service at noon at Sound Beach Veterans Memorial Park, New York Avenue, 631-922-3773.

Begins at 10:45 a.m. at the First Presbyterian Church, 2 S. Main St., then heads to Agawam Park for a memorial service at 11 a.m., 631-283-0247.

Assemble at 9 a.m., steps off at 10 a.m. at Woodlawn and Lake avenues, and proceeds to St. James Elementary School for a ceremony, sponsored by VFW Post 395.

Begins at 10 a.m. on Dawes Avenue to Memorial Park, Underhill Boulevard and Jackson Avenue, where a brief ceremony takes place. An unveiling of a wall mural made by local middle school students follows at the VFW Post, 20 Queens St.

Assembles at 9:30 a.m. on Beltagh Avenue by Wantagh Middle School, parade begins at 10 a.m. and ends at American Legion Post 1273, 3484 Park Ave., where a ceremony follows, 917-681-4050.

Assembles at Arnold Avenue and Route 109 at 9 a.m., parade begins at 10 a.m. and proceeds to American Legion Post 1634, 10 Bruce St., for a service, 631-669-3931.

Begins at 10 a.m. at St. Thomas the Apostle Chapel, Hempstead Avenue and Nassau Boulevard, and heads to the American Legion, 233 Woodlawn Rd.

WESTBURY

MASS Service held at Holy Rood Cemetery, 111 Old Country Rd., at 9:30 a.m., 516-334-7990.

WILLISTON PARK

SERVICE AND PARADE Service starts at 9 a.m. at American Legion Post 144, 730 Willis Ave., parade follows from Broad Street and ending at Village Hall, hosted by American Legion Post 144, 516-746-1958.

ROCKY POINT

PFC. JOSEPH P. DWYER PTSD MEMORIAL 5K RUN Begins at 12:30 p.m. at Rocky Point High School, 82 Rocky Point Yaphank Rd., $35, strongislandrunningclub.com, 631-744-9106, 631-744-8539.

Compiled by Gina Tabarus with Diane Daniels, Sabrina Monroe, LaToya Rodriguez and Daniel Variano