Baseball’s original home run king was a huge man who hit the major leagues’ first grand slam and later added a tape-measure shot so thrilling that fans passed the hat, collected $500 and bought their hero a gold watch in tribute.

No, it wasn’t Babe Ruth.

The Babe wasn’t even born when Roger Connor began slugging away. Connor was the hero of the horse-drawn carriage crowd, a star among the ragtag community of transients and miscreants who played baseball before the turn of the 20th century.

And he hit the princely total of 138 home runs – more than anybody until Ruth came along.

Connor stood 6-foot-3 and weighed 220 pounds, his profile accented by a handsomely groomed handlebar mustache that he wore proudly in the style of the day. Blessed with speed and power, he had a demeanor that helped bring respectability to baseball.

He was just the kind of standout slugger the game needed to win acceptance in post-Civil War America, which had its doubts about the sport. Nobody, however, doubted Connor, who began his career in 1876 with the Waterbury Monitors of the Eastern League, playing third base even though he was left-handed.

Connor didn’t switch to first, a more appropriate position, until 1881 with Troy. The change was prompted not only by a shoulder injury but also by 60 errors in 83 games the previous year.

The switch also enabled Connor to concentrate on his hitting and that would be the hallmark of his career. On Sept. 9, 1881, he became an icon for every slugger in history with baseball’s ultimate home run – a game-winning grand slam with two outs in the bottom of the ninth inning.

Troy was trailing Worcester 7-4 and down to its last out when Connor came to bat with the bases loaded against John Lee Richmond, who had thrown baseball’s first perfect game a year earlier. Connor turned on one of Richmond’s pitches and delivered the first slam recorded in baseball history.

Not only were players transients, but so were franchises. A year after Connor’s landmark shot, Troy faded away, and he surfaced with several other teammates on New York’s new National League team. The Gothams played in the original Polo Grounds and on Sept. 11, 1886, Connor muscled a home run that sailed clear out of the park.

“He was the first power hitter of the game,” said Bernard Crowley, who profiled Connor for the Society for American Baseball Research. “He was one of the most popular players of his time.”

Home runs and records became more widely documented when Ruth started accumulating them and on July 18, 1921, the Babe passed Connor with No. 139 in a career that would ultimately produce 714.

Connor’s accomplishments were washed away by the sands of time and he was buried in an unmarked grave in St. Joseph’s Cemetery in Waterbury, Conn.

Slowly, as historians began studying the game more closely, Connor’s achievements were noticed. In 1976, two years after Hank Aaron eclipsed Ruth’s record, baseball’s first home run king was elected to the Hall of Fame by the Veterans’ Committee.

“And now,” Crowley said, “there’s a gravestone for him at St. Joseph’s.”