NATICK, MA -- When U.S. Army Staff Sergeants Robert Keifer and Anthony Sandoval decided to reenlist, they wanted to swear in at a location with historical significance to their current duty station, service branch and country.As noncommissioned officers stationed at the only active duty Army base in New England - the Natick Soldier System Center in Natick, Massachusetts -- the natural choice was Minute Man National Historical Park, where the battles of Lexington and Concord were fought to begin the American Revolutionary War.And so, standing on the battle's famous North Bridge crossing the Concord River, where the "shot heard round the world" was fired, Keifer and Sandoval recited the oath of enlistment in front of a small crowd of fellow Soldiers, co-workers, family members and tourists, as another Soldier waved a 13-starred, colonial era, "Betsy Ross" flag behind them.As NCOs for the U.S. Army's Natick Soldier Research, Development and Engineering Center, or NSRDEC's Headquarters Research and Development Detachment, Keifer and Sandoval provide daily supervision to new Soldiers serving in the Human Research Volunteer Program. The assignment allows them to take in the rich history of the region."The reason we chose this location is the historical significance and because Sandoval and I both like Revolutionary War history," said Keifer. "To reenlist where 'the shot heard round the world' was fired has meaning, and obviously, it's a very scenic spot.""This is where our country, where the fight for independence, really began," Keifer said.---The U.S. Army Natick Soldier Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to provide innovative research, development and engineering to produce capabilities for decisive overmatch to the Army against the complexities of the current and future operating environments in support of the Joint Warfighter and the Nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.