The dawning of the expansion era in major league sports had been kind to Minnesota.

The National Football League added two teams, the Vikings and the Dallas Cowboys, as a reaction to the fledgling American Football League.

The American League added teams in Washington, D.C., and Los Angeles, to accommodate owner Calvin Griffith’s move of the Washington Senators to Minnesota. Griffith’s Twins played their first home opener against the new Senators on April 21, 1961.

The expansion Vikings played for the first time at Met Stadium in an exhibition with the Los Angeles Rams on Sept. 10, 1961. The Twin Cities were now in the major leagues, and yet we still were a wayside rest on the prairie to the nation’s sports fans.

If people were paying attention, you wouldn’t have heard so many references to the Twin Cities as St. Paul and “Minnyunapolis.” Really. We had the major league teams and were poor cousins to Indianapolis in national perception.

I have a date when Minnesota went from a place with baseball and NFL franchises to a feeling that we had arrived, that we were truly major league. It was 50 years ago this weekend. It was July 11, 1965, a sun-filled afternoon with the temperature headed toward 80 degrees.

The Yankees had won five consecutive American League pennants and added two World Series victories to their collection from 1960 to 1964. In the first four seasons Minnesota was in the league, the Yankees’ victory totals were 109, 96, 104 and 99.

The Twins had fallen back from the 91-win seasons of 1962-63 to a 79-83 record in 1964. Attendance also had fallen from 1.4 million to 1.2 million.

The Twins had made an interesting deal in the middle of 1964 — acquiring starter Mudcat Grant from Cleveland — but didn’t change much in the offseason.

As the Twins went through 1965 spring training in Orlando, Griffith had more to worry about than his decisions to stick with manager Sam Mele and a nucleus of players that had finished in the second division, 20 games behind the Yankees.

The Twins owner also was fretting the weather reports from the Twin Cities. There was a St. Patrick’s Day blizzard, followed by more substantial snowfalls. By late March, the Met Stadium field was covered by three feet of snow and ice.

This also was the rare season in Met Stadium history (1961-81) when the Twins were scheduled to open at home: April 12 vs. the Yankees.

The good news was there was a quick thaw in early April. The much worse news was that this caused record floods in the Twin Cities. If you lived in the south suburbs, you had to figure out a way to get to the Mendota Bridge to get across the Minnesota River.

The Twins decided to go ahead with the opener, even though people were going to have a hellacious time getting to the ballpark. The group of harried commuters included Jim Kaat, the Twins’ scheduled starting pitcher.

Kaat was living in Burnsville, as were third baseman Rich Rollins, infielder Bill Bethea and pitcher Dick Stigman. The roads were flooded. Kaat called WCCO Radio, where former teammate Paul Giel was working, and asked about the news helicopter that the TV station had used.

Giel sent the helicopter. Kaat and the other Burnsville residents were brought to the ballpark two at a time. Kaat made his start and the Twins beat the Yankees 5-4 in 11 innings.

The Twins postponed a couple of games that week because of the floods. When they did play, things went well. The Twins went to New York on April 21-22 and knocked around the Yankees 7-2 and 8-2.

• • •

The Twins moved into first place — one league, 10 teams — on Memorial Day weekend and stayed there.

They came home on July 5 and gained a 1½-game lead by sweeping a split doubleheader from Boston.

Impressed? Don’t be. The Twins went 17-1 against the woebegone Red Sox (62-100) that season, winning the last 15 meetings.

The homestand called for four games against Boston, four against the Yankees, followed by the All-Star Game at Met Stadium.

The Yankees were 12½ games back and in sixth place when they arrived at Met Stadium on July 9. Mickey Mantle was 33, his legs were shot and he was in steep decline. So was Elston Howard.

The Bronx Bombers were descending into what became known as the “Horace Clarke Era,” but we didn’t know that in midsummer of 1965. These were the Yankees and we didn’t trust ’em.

We wanted to kill the Pinstripes in this four-game series. With the All-Star Game on the horizon, what amounted to the national baseball media started to assemble at Met Stadium that weekend, to check out this Minnesota bunch.

The Twins won with Dave Boswell on Friday, they split a day-night doubleheader in front of crowds over 36,000 on Saturday, and then came Sunday … then came the last inning, the last out, the last pitch, before the All-Star Game would be played and the spotlight would shine on our prairie ballpark.

The Yankees scored in the ninth on an error by reliever Jerry Fosnow for a 5-4 lead. Pete Mikkelsen arrived for the bottom of ninth. Rollins drew a one-out walk and then Tony Oliva flied to center.

That left Harmon Killebrew to face the righthanded Mikkelsen.

Twins fans in the 30- to 55-year-old demographic have Kirby Puckett’s home run off Charlie Leibrandt in Game 6 of the 1991 World Series. Golden Agers have Harmon’s home run off Mikkelsen two days before the 1965 All-Star Game.

Two outs, 3-2 count. If you haven’t heard Twins announcer Ray Scott’s call of Harmon’s blast, find it. I was a fan then, not an objective media member, and still can get chills listening to Ray’s setup.

The Twins’ 6-5 victory put them in first place by five games at the break, and 14½ games in front of the Yankees. And now we knew it:

We were home to the major league team that had slain the Yankees.

• • •

Years later, I tracked down Mikkelsen (now deceased) to talk about Killebrew’s home run. His reaction was outstanding.

“Every time I run into someone from Minnesota, they mention that home run,” Mikkelsen said. “I gave up a home run to Harmon Killebrew. So did a couple of hundred other guys.

“What’s wrong with you people?”

Nothing, Pete. Not after that home run.

Two days later, there was a fabulous All-Star Game, with another Killebrew home run and a 6-5 victory for Willie Mays and the National League, and that fall there was a fabulous World Series, won by the Dodgers and Sandy Koufax 2-0 in Game 7, and all of it was more fun than frustrating.

1965. The Twin Cities went from being in the major leagues to major league.

Heck, we even had the Beatles that summer: Aug. 21 at Met Stadium.

Eleven songs, tickets from $2.50 to $5.50, 25,000 people, and the Beatles vamoosed with $50,000 of our hard-earned money.

And I think many of our parents were overheard to say: “For that kind of money, you would think they could afford haircuts.”