Anniversaries are the mainstays of stamp topics for countries throughout the world. Commemorations of famous people's birthdays, special historic dates for proud nations and significant honors for organizations that contribute greatly to the benefit of mankind have been highlighted on the postage stamps of the world.

"Anniversaries," consequently, is the theme of the latest set of stamps issued by the West African land of Gambia, a former British colony. The set consists of eight adhesives and two souvenir sheets that highlight major historical and aviational anniversaries.The 50-butut stamp depicts the flag of the International Red Cross on its 125th anniversary (1863-1988).

The 1-dalasy features a British Airways Concorde on its 10th anniversary flight from London to New York.

The 1.25-dalasy hails the 60th anniversary of Col. Charles A. Lindbergh's solo flight across the Atlantic. Shown on the stamp is the "Spirit of St. Louis." (The 60th anniversary actually took place last year but the Gambia postal authorities liked the idea of the anniversary for this stamp set.)

The 2-d illustrates the flight of the North American X-15 by Maj. William Knight of the U.S. Air Force when he attained the fastest speed ever achieved by an airplane. It notes the 20th anniversary of the event.

The 3-d pictures the 40th anniversary of the first supersonic flight by Chuck Yeager of the United States. Yeager piloted the Bell X-1 rocket-powered research aircraft to a speed of Mach 1.015 (670 miles per hour) at an altitude of 42,000 feet.

The 10-d marks the 400th anniversary of the defeat of the Spanish Armada by the British in 1588. Shown is a scene of the famous battle at sea.

The 75-butut depicts the Friendship 7 spacecraft piloted by U.S. astronaut John Glenn into three orbits around the earth. The stamp honors the 25th anniversary of the first American to make that orbit.

The highest value, 12-dalasy, marks the 75th anniversary of the sinking of the British liner Titanic, which went down on its maiden voyage.

The stamps are available at your local dealer.

* The Postal Service will pay tribute to the bicentennial of New Hampshire, "the state that made us a nation," with a 25-cent commemorative.

On June 21, 1788, New Hampshire became the ninth and deciding state to ratify the Constitution of the United States.

Depicted on the new 25-cent commemorative is "The Old Man of the Mountain," the famous rock formation at Franconia Notch. Considered New Hampshire's best known natural wonder, the same "Old Man" appeared on a 3-cent New Hampshire stamp issued in 1955.

The latest design is based on an original painting by Thomas Szumoski. The features of the state's stone patriarch appear in varying shades of granite gray against a blue background.

New Hampshire is said to have struck the first blow for American independence, capturing Fort William and Mary on Dec. 14, 1774.

First-day cancellations are available.

Collectors who prefer to affix their own stamps may purchase them at their local post offices and place them on their own envelopes. Requests must be postmarked by July 21. Send to: Customer-Affixed Envelopes, New Hampshire Statehood Stamps, Postmaster, Concord, NH 03301-9991. No remittance is required.

To have the USPS affix the stamp, enclose a money order or personal check for 25 cents per stamp and send to: New Hampshire Statehood Stamps, Postmaster, Concord, NH 03301-9992. The deadline is July 21.

* For trivia buffs, the 1955 New Hampshire 3-cent stamp featuring the "Old Man" design was issued to honor the sesquicentennial of the discovery of the famous rock formation at Franconia Notch.

* North Carolina artist Bob Timberlake designed the South Carolina statehood stamp being issued on the 200th anniversary of the state's ratification of the Constitution. The stamp, the 10th in the series of commemoratives honoring the 13 original states, features palmetto trees.

For first-day cancellations, write to: Customer-Affixed Envelopes, Statehood Stamp, Postmaster, Columbia, SC 29201-9991, or Statehood Stamp, Postmaster, Columbia, SC 29201-9992.