July Fourth Celebrates a Newer World : Holiday: Replicas of Columbus’ ships float in New York Harbor as Columbia astronaut sends a message from high above the fireworks.

Five hundred years after Columbus sailed the ocean blue, his ships bobbed in the harbor greenish-brown--that’s New York--to celebrate the Fourth of July. High above, modern-day explorers were spending the holiday aboard a new ship: the space shuttle.

Columbus wouldn’t have had a clue.

The old explorer probably would have recognized the replicas of the Nina, the Pinta and the Santa Maria that were docked in New York Harbor for Operation Sail ‘92, the huge parade of ships planned for July Fourth.

That’s about where it would have ended.

He hardly would have understood what the fuss was all about, since the Declaration of Independence--signed 216 years ago today--was still 284 years in the future when Columbus made his first voyage to the Americas.

Still, there was a spirit of exploration that Columbus might have recognized in some July Fourth celebrations.

There was Freedom Weekend Aloft, the annual hot-air balloon festival in Greenville, S.C.

And there was the Madison Regatta for unlimited hydroplanes in Madison, Ind., this year featuring the U-50 American Spirit, a red, white and blue hydroplane sponsored by supporters of Ross Perot, the exploratory presidential candidate.

Holiday festivities got off to an early start in a few places, including Detroit and New York, which held fireworks shows Thursday night.

The big show is today in New York Harbor, where what is billed as the largest collection of tall ships ever is sailing in a quincentenary tribute to Columbus.

The 34 tall ships are expected to attract 40,000 smaller boats to the harbor, plus 1 million spectators to the shores and enough cars to the streets to remind people that the Age of Exploration has become the Age of Gridlock.

Up above, the astronauts aboard Columbia--named for a ship used in the exploration of the Northwest in 1792--will be celebrating; they are only the second American crew to spend Independence Day in space. In 1982, Columbia returned to Earth on July Fourth.

Commander Richard N. Richards reflected on Columbus’ voyage in a radio interview Friday:

“To me, it’s worth celebrating the 500th year of Columbus discovering the New World and investing in things like the Nina, Pinta and Santa Maria. There was absolutely the possibility of no return for that, but we invested in that and found some things that we weren’t really planning on.”

Retired Supreme Court Justice Thurgood Marshall, a longtime champion of civil rights, will receive the 1992 Philadelphia Liberty Medal today in a Fourth of July ceremony in the cradle of liberty.

The $100,000 award was first given to Poland’s President Lech Walesa in 1989.

It honors “an individual or organization from anywhere in the world that has demonstrated leadership and vision in the pursuit of liberty of conscience or freedom from oppression, ignorance or deprivation.”

Marshall, 84, an NAACP lawyer for more than 20 years, argued the 1954 landmark case Brown vs. Board of Education that ended “separate but equal” schools.

He played a key role in the integration of Little Rock Central High School in 1957 and was instrumental in fights against the poll tax and racial restrictions in housing and public universities.

President Lyndon B. Johnson appointed Marshall to the Supreme Court in 1967 as the first black justice.