Pitchers in this era threw underhand; but there were fair and foul balls. The positions were the same, although sometimes the second baseman played closer to that base, and the shortstop played in the outfield.
“It would have probably resembled a Sunday morning old guy’s softball game,” says George B. Kirsch, professor of history at Manhattan College and author of Baseball in Blue & Gray: The National Pastime during the Civil War. “The idea was to get the ball into play, so scores were usually pretty high.”
In his book, Kirsch describes the Massachusetts game--the other major style of baseball at the time --as being descended from a bat and ball game that was played in New England as far back as the 1700s. The Massachusetts style of baseball he presents as "similar to New England townball, with a square field, overhand pitching, no foul territory, ten to twelve men per side, one out to retire all and victory belonging to the team that first scored one hundred runs."
Given the popular preference for the New York brand of baseball, it was no accident that the game held on Christmas Day was between teams representing New York regiments, Mills’ 165th, and a “nine” composed of members of the 47th and 48th New York.
The game’s attendance has sparked debate over the years. Some say that it couldn’t have possibly been the 40,000 or even 50,000 mentioned by Mills and others. Baseball writer Alex Remington, writing about the Christmas Day game on Fangraphs, in December, 2011, is suspicious because of what he calls “the unreliable source at the heart of the story.” That would be Mills who, in the early 1900s, was appointed head of a committee that sought to investigate the origins of baseball, and came up with the now widely discredited fable of the game having been invented in Cooperstown, New York, by Abner Doubleday (himself a Union Army general during the war.)
While Mills may or may not have embellished the size of the Christmas Day game, Smith thinks that higher attendance numbers are entirely plausible, pointing out that in addition to the troops on the island, there were thousands of freed slaves, civilian workers, teachers and their families, and Confederate prisoners of war. Moreover, the extensive dunes on Hilton Head at the time would have provided excellent, elevated seating for spectators. The natural undulations of the dunes would have also allowed for more easy segregation, enabling African Americans to watch, as well as whites (while slavery had been abolished in April 1862 the Sea Islands, of which Hilton Head is one of, there was still little socializing between the races).
"The controversy about the number of people that could have attended is interesting,” says Smith. “So few think about the number of freed slaves there were on the Island at the time. The officers could have brought their wives. Or the prisoners on the island. All of these people could have very well attended.”
Whether it was 10 or 20 or 40,000 in attendance, it is likely that many in the crowd were exposed to the New York game of baseball for the first time that day—or at least, got to see it played proficiently. If, as Kirsch says, the Civil War is often seen as having advanced baseball’s popularity throughout America, then the most widely attended game of the war must have had some impact.
Still as Smith says, “it was a one day event to amuse the troops.” Nor was baseball the only entertainment—and maybe not even the most popular. According to a 2010 article in the local Hilton Head paper about the game, the Union-run newspaper on the Island mentioned the game (no crowd figure), but noted that it was played "after a demonstration of fire engines and a huge meal." The game was likely the culminating event in a day's program of activities.
While the Union encampment had no designated ball field (most likely the teams played on an open space or one of the parade grounds), they did have the Union Theater where, for the price of a 50 cent ticket, audiences could enjoy a performance of such dramatic fare as “Temptation of the Irish Immigrant.” Consider that in the regimental history of the 48th New York Volunteers, published in 1885, a mere paragraph is allotted to their baseball “nine”—and no mention at all is made of the Christmas Day game.