Two hundred years ago, the "Federalist" papers - considered to be the most important writings in American political science - were printed and distributed in New York in defense of the newly created Constitution of the United States.

As a tribute to these essays and their writers, the U.S. Postal Service has issued a new 15-cent postal card. It features a stylized painting of a newspaper hand press used in Colonial times. In the foregorund, a pressman prints a copy of a newspaper that carried the "Federalist" papers in 1787-88, while in the background, a man examines the issue. In the upper right corner of the illustraion is "USA 15."The "Federalist " papers, a series of 85 essays, were written by such prominent Colonial Americans as Alexander Hamilton, James Madison and John Jay.

According to the Postal Service, the "Federalist" papers remain a classic treatise in American political theory, and are the most widely read and referenced commentary on the Constitution. They are cited by lawyers, judges and political scholars to explain the Constitution's mandates and to enunciate its doctrines.

First-day cancellations are available in the two usual ways.

You may buy the 15-cent card at your local post office and submit it for cancellation. No remittance is required. Send the card to: Customer-Provided Stationery, Postmaster, New York, N.Y. 10199-9991. It must be postmarked by Nov. 26.

Collectors who prefer that the Postal Service provide the card should send an envelope with self-addressed labels and a money order or personal check for 15 cents per card. Send to: "Federalist" Papers Postal Card, Postmaster, New York, N.Y.10199-9992. The deadline is Nov. 27.

A popular song describes San Francisco as a place "where little cable cars climb halfway to the stars."

Those famous cable cars, which were invented in San Francisco and are still in use today, are hailed on a new 20-cent stamp. Its illustration is a composite drawing of cable cars from the 1880s, primarily the No. 46 "dummy" car, which carried a few passengers and pulled other cars.

The stamp's 20-cent denomination meets the rate for the second ounce of first-class mail. The stamp design is the first for California artist Dan Romano.

The single-color stamp shows a cable car riding over the crest of an incline, common in the San Francisco area. The inscription "Cable Car 1880s" appears in purple at the bottom of the stamp. Above it appears "USA 20."

San Francisco's unique cable car system operates with 37 cars on a 10-mile network. These cars reach a speed of only 9.5 mph. Each year, 19 million passengers enjoy the clanging and lurching, and the fun - a living history of the "City by the Bay."

First-day cancellations of the Cable Car stamp are available.

Collectors who want to buy the stamp at their local post office and affix to their own envelope must remember to add 5 cents postage to meet the minimum first-class mail rate. Send to: Customer-Affixed Envelopes, Cable Car Stamp, Postmaster, San Francisco, CA 94188-9991. No remittance is required. Requests must be postmarked by Nov. 27.

The 1988 Commemorative Mint Set featuring the 40 U.S. commemoratives issued during the past year, plus interesting background information and dramatic, full-color illustrations should be available after Nov. 1 at all Philatelic Centers and most larger post offices, as well as by mail from the Philatelic Sales Division.

The set is priced at $14.50 for the soft-cover edition and $21.50 for the deluxe, hard-bound edition. Each contains the 40 stamps with individual protective mounts.

Included in the 32-page collection are singles of the four Special Occasion designs, a booklet pane of the five Classic Cars stmaps, and the 1988 contemporary and traditional Christmas stamps.

Collectors desiring to order by mail should enclose a personal check or money order for $14.50 or $21.50, depending on which version you want, plus 50 cents for handling. Send orders to: Philatelic Sales Division, Washington, DC 20265-9997.

The Mint Set makes an ideal holiday gift for collectors.