The Giants brought the 1951 pennant west, but the home run stayed in New York

Bobby Thomson played third base in the last game the Giants played as New York's team.

That was September 29, 1957, a Sunday at the Polo Grounds. Pittsburgh won 9 to 1, and Thomson had one of the six Giants hits. He had been traded to Milwaukee in February 1954 and traded back in June 1957, so the man who won the 1951 pennant with one swing was on the field for the franchise's final afternoon as the home team in the city where he did it.

On April 3, 1958, the club sent him to the Chicago Cubs for Bob Speake and cash. The club making that trade was the San Francisco Giants. Twelve days later it played its first game in California, an 8 to 0 win over the Dodgers at Seals Stadium, and Thomson was a Cub. He never played a regular-season game for San Francisco.

His home run turned 75 on Saturday.

The afternoon fits in a sentence. On October 3, 1951, in the bottom of the ninth inning of the third game of a playoff for the National League pennant, with one out, two on and the Giants two runs down, Thomson hit a home run to left field off Ralph Branca, and the Giants beat Brooklyn 5 to 4 in front of 34,320 people.

Where it was on Saturday#

The bat is in Cooperstown. The National Baseball Hall of Fame keeps it on the museum's second floor, and the program the Hall announced for the anniversary featured it along with Russ Hodges's scorecard from the game and an interview with Thomson's daughters, Megan Hann and Nancy Mitchell.

The people who remember it were reached through New York. Michael Clair of MLB.com went looking for them and had help from Gary Mintz of the New York Giants Preservation Society. Most had been children then, in the Bronx and in Brooklyn, in Bayonne and in New Haven. One of them watched on his tiptoes at a five-and-dime. Clair's two pieces ran on the San Francisco club's own news page, and San Francisco is not mentioned in either.

The ground is in Harlem. The Polo Grounds came down in 1964, and four public housing towers were finished on the site in 1968 and named for it. A bronze plaque was made for the towers to mark roughly where home plate was. It was restored last year in an effort led by Michael Mays, the son of Willie Mays, with the city's housing authority and the Preservation Society, and unveiled on September 6, 2025.

Consider what that society is. It preserves a baseball team that is still playing. Mintz, its president, said so to MLB.com in 2014: "There was a team here and that team still exists even though they're 3,000 miles away."

What moved#

A franchise carries its papers when it moves. The 1951 pennant sits in the San Francisco Giants' record book because a record book is property, and property goes where the owner goes. An afternoon is something else. It happened to the people who were listening, in the places where they were listening, and the record since 1958 says the home run stayed with them. San Francisco has done well by it as a guest, and came away without the man who hit it when it tried to play host.

San Francisco's side of this is real. Willie Mays was the next batter when Thomson swung, and he played center field for San Francisco from 1958 into 1972. Hodges called the home run and then called Giants games in San Francisco through 1970; he died in Mill Valley the following April. Bill Rigney pinch-hit in the eighth inning that day and managed the first San Francisco team. Alvin Dark, who opened the ninth with a single, managed San Francisco to the 1962 pennant. The men came west, and the day came with them as their own.

In 2001 San Francisco sent for the day itself. There were to be fiftieth-anniversary festivities at a Giants-Dodgers game in San Francisco, rescheduled after the September 11 attacks, and Thomson declined to attend. Dave Anderson wrote in The New York Times that October that Branca's feelings were a factor, and he quoted Thomson on the plan. "They were going to have Ralph and me ride around in a cart," Thomson said. "Ralph doesn't need that."

In 2011 the club went the other way. On January 21, 2011, it carried the 2010 World Series trophy to P.S. 46, a public school next to the towers, and Willie Mays went with it. "This is my neighborhood," Mays said there, in Sports Illustrated's account. That November Fox Sports reported that the club had put $50,000 toward rebuilding the John T. Brush Stairway, which runs down Coogan's Bluff toward where the ballpark stood and which the city's parks department calls the last remnant of the Polo Grounds. A club spokeswoman, Staci Slaughter, said it would be "highly appropriate for us to participate." The job was budgeted at $950,000 when work began. The football Giants gave $200,000, and the Yankees and the Mets gave $100,000 each. The baseball Giants gave what the Jets gave.

The restoration kept the original brass lettering, set in a landing halfway down. It says the stairway was presented by the New York Giants.

April 15, 1958#

San Francisco's first lineup had Mays in center field and Rigney in the dugout. Jim Davenport played third base. The third baseman from the last afternoon in New York was twelve days gone, in another uniform, and the home run was where he had left it.

Sources: Retrosheet box scores and play-by-play for October 3, 1951, September 29, 1957 and April 15, 1958; the Society for American Baseball Research's biographies of Bobby Thomson (trades of February 1954 and June 1957) and Russ Hodges; Dave Anderson, The New York Times, October 1, 2001, on the 2001 anniversary; Baseball-Reference for the trade of April 3, 1958; the National Baseball Hall of Fame's announcement, September 24, 2026, of its 75th-anniversary program; the New York City Housing Authority's development data, for the towers; Michael Clair, MLB.com, October 2, 2026; the NYCHA Journal, September 11, 2025, on the home plate plaque; Paul Post, MLB.com, September 9, 2014, on the reopened Brush Stairway, for Gary Mintz and the brass lettering; Sports Illustrated, January 24, 2011, and WCBS 880, January 20, 2011, on the trophy at P.S. 46; Fox Sports, November 7, 2011, and NYC Parks, July 10, 2015, on the stairway and who paid for it.