At 12:38 a.m. on April 14, 1860, the steamer Antelope pulled up to the Broadway wharf. It was carrying a small, gaily bedecked bay horse and rider, who earlier that day had galloped into Sacramento — the last relay station on a transcontinental journey that had begun in St. Joseph, Mo., 10½ days, 1,950 miles and 75 ponies away.

The first run of the Pony Express had been completed, and San Francisco was about to throw one of its most memorable parties.

As related in the last Portals, San Francisco in 1860 was still profoundly isolated from the rest of the country. There was no railroad or telegraph west of the Missouri River, and mail took at least three weeks to arrive from the East.

So the Pony Express, a wildly ambitious enterprise that promised to cut that delivery time in half, fired the imagination of the residents of America’s most far-flung city. The Alta California newspaper wrote, “One by one the chains of darkness and the desert are broken, and we are brought nearer and nearer to our brethren on the other side of the continent.”

The final legs of the run had been triumphant, like the entrance into an Olympic stadium by the leader in the marathon. The citizens of Placerville had turned out in force the afternoon before, waving handkerchiefs as “the Pony Express shot like an arrow though the crowd,” the Mountain Democrat wrote. In Sacramento, the final land station, crowds cheered as a pony ridden by William Hamilton “was seen coming at a rattling pace down J Street,” riding through a sea of American flags.

San Franciscans had been alerted by the press that the steamer with the pony would arrive from the state capital around midnight, and a committee was convened to plan a greeting. The committee sent messages to fire engine companies, procured fireworks, and made announcements from the stages of the major theaters, “to much applause.”

At 11 p.m., an 18-piece band started from Sacramento and Montgomery streets. “Perambulating the streets, (it) soon gained a large assemblage, all on the qui vive to welcome the Pony Express on its arrival,” the Alta reported. “Bonfires were lighted in various places, which told with remarkable effect in the dark night. The Monumental bell occasionally rang out its merry peal, and (Fire Station) Five’s boys, dressed in their uniforms, ran out their engine for the lark of the thing, racing at full speed around the block bounded by Montgomery, Sansome, Sacramento and Clay. ... The whole lower part of the city was in motion, and the crowd was greatly augmented by the audiences from the theaters.”

Half an hour before midnight, the procession began moving. It started on Montgomery and marched past fire stations, picking up more celebrators from each, until the crowd numbered 2,000. The streets in all directions were lit up with bonfires. At midnight, the procession moved down to the Broadway wharf, as the California Band played “splendid marches and martial airs.”

Cheers filled the air as the Antelope hove into view a few minutes later. After the steamer docked, the bay horse with its precious mochila — the leather mail bag — was triumphantly placed in the center of the procession, preceded by the band and the fire engines, with the crowd bringing up the rear. A woman took off her bonnet and tied it around the pony’s neck.

As the band played “Hail the Conquering Hero,” the procession moved to the Pony Express’ final destination, the Alta Telegraph Co. at the corner of Montgomery and Merchant. Once the pony arrived at the building, which was festively lit up with candles, the 25 letters it carried were ceremoniously delivered.

The Pony Express’ epic journey was complete, but San Francisco’s party was just beginning. Because of the late hour no prepared speeches were made, but a number of “impromptu addresses” were delivered. The Sacramento Union reported that “all took a drink at their own expense,” adding that those present were “pleased with themselves and the rest of mankind, and the Pony Express in particular.”

The Alta wrote, “Until the ‘wee sm’ hours this morning the boys were ‘running,’ and in various boisterous styles, and harmless ways, manifesting their appreciation of the great event they had all been witnessing.”

The Pony Express’ moment was brief. It was killed by the telegraph. On Oct. 26, 1861, just two days after the transcontinental telegraph line was completed — an event marked by a telegram sent from San Francisco to President Abraham Lincoln — it went quietly out of business. It had been in service just 78 weeks.

The Western press wrote heartfelt eulogies. “Our little friend the Pony is to run no more,” the Sacramento Bee editorialized. “Rest, then, in peace, for thou hast run thy race, thou hast followed thy course, thou hast done the work that was given thee to do.”

Perhaps more than any other event in the history of the Old West, the Pony Express retains its capacity to inspire. There are many reasons for this, but probably the most important is its innocence.

As Christopher Corbett writes in “Orphans Preferred: The Twisted Truth and Lasting Legend of the Pony Express”: “It was a splendid moment of history, a rare event where the taming of the West took no victims.”

The Pony Express killed no Indians, despoiled no land. It took the measure of America’s spirit, and found it great. Its thundering hooves resound forever in the imagination, an elegy for a country that would never be so vast, or so young, again.

Gary Kamiya is the author of the best-selling book “Cool Gray City of Love: 49 Views of San Francisco,” awarded the Northern California Book Award in creative nonfiction. All the material in Portals of the Past is original for The San Francisco Chronicle. Email: metro@sfchronicle.com

Trivia time

Previous trivia question: How did Visitacion Valley get its name?

Answer: In 1777, a party of Spanish soldiers and friars on their way to the Presidio got lost in a heavy fog near San Bruno Mountain and camped. The next morning they beheld a beautiful valley. Because it was July 2, the Feast of the Visitation of the Virgin Mary, they named it Visitacion Valley.

This week’s trivia question: Who happily strummed a guitar as he strolled down Haight Street on Aug. 7, 1967?

Editor’s note

Every corner in San Francisco has an astonishing story to tell. Gary Kamiya’s Portals of the Past tells those lost stories, using a specific location to illuminate San Francisco’s extraordinary history — from the days when giant mammoths wandered through what is now North Beach to the Gold Rush delirium, the dot-com madness and beyond. His column appears every other Saturday, alternating with Peter Hartlaub’s Our San Francisco.