Question: Columbus Crew SC has a head coach who is of what heritage?

Context paragraphs:
Brad Stuver: Bradley "Brad" Stuver (born April 16, 1991) is an American professional soccer player who plays as a goalkeeper for Columbus Crew SC in MLS, and is currently the goalkeepers coach at Ohio Wesleyan.

Josh Wolff: Joshua David "Josh" Wolff (born February 25, 1977) is a retired American soccer player who now works as an assistant coach for Columbus Crew SC of Major League Soccer.

Lamar Hunt Pioneer Cup: The Lamar Hunt Pioneer Cup is a Major League Soccer (MLS) series between FC Dallas and Columbus Crew SC.  The series is named after the late Lamar Hunt, who was one of the league's early major investors and a key supporter of American soccer.  Initially, the series was contested between the two teams still owned by the Hunt Sports Group (Sporting Kansas City was also previously owned by the Hunt Sports Group, but was sold before the Pioneer Cup began).  However, Columbus was sold in 2013, and thus FC Dallas remains the only MLS team still owned by the Hunt Sports Group.  The Pioneer Cup is the second event in American soccer named after Lamar Hunt, whose name is also given to the Lamar Hunt U.S. Open Cup.

MLS Cup 2015: MLS Cup 2015 was the 20th edition of MLS Cup, the championship game of Major League Soccer (MLS).  The match was to determine the champion of MLS' 2015 season.  The championship was contested on December 6, 2015 between the Columbus Crew SC and the Portland Timbers at MAPFRE Stadium in Columbus, Ohio, with the latter winning 2–1 and earning a berth into the 2016–17 CONCACAF Champions League.

Hudson Street Hooligans: The Hudson Street Hooligans (HSH) are an independent supporters group for Columbus Crew SC of Major League Soccer.  They are named for Hudson Street, which runs adjacent to Mapfre Stadium in Old North Columbus.

List of Columbus Crew head coaches: Columbus Crew SC is a professional soccer team in the United States.  The team is a member of the Eastern Conference of Major League Soccer, the top professional soccer league of the United States and Canada.  Crew SC has had five different head coaches since joining the league in 1996.  Timo Liekoski, the only Finnish head coach in MLS history, was the first head coach in 1996, but started 6-16 and was fired midseason to be replaced by Tom Fitzgerald.  Fitzgerald is currently the all-time leader in regular season wins (70), playoff appearances (four) and playoff wins (nine).

Mapfre Stadium: Mapfre Stadium ( ; styled as "MAPFRE Stadium"), previously known as Columbus Crew Stadium, is a soccer-specific stadium in Columbus, Ohio, United States.  It primarily serves as the home stadium of the Columbus Crew SC of Major League Soccer.  Mapfre Stadium is also the site of a variety of additional events in amateur and professional soccer, American football, lacrosse, and rugby, and is a regular site for outdoor concerts due to the permanent stage in the north end zone.

Columbus Crew SC: Columbus Crew Soccer Club is an American professional soccer club based in Columbus, Ohio.  The Crew competes in Major League Soccer (MLS) as a member club of the league's Eastern Conference.  The Crew began play in 1996 as one of the ten charter clubs of the league.  The team is owned by Anthony Precourt and Precourt Sports Ventures LLC.  Precourt became the second owner in the history of the club on July 30, 2013.  The club's head coach is Gregg Berhalter, a former player of the United States men's national soccer team.

Gregg Berhalter: Gregg Berhalter ( ; born August 1, 1973) is a retired American soccer player and current head coach of Columbus Crew SC in Major League Soccer.

Pittsburgh Riverhounds: The Pittsburgh Riverhounds are an American professional soccer team based in Pittsburgh, Pennsylvania.  Founded in 1998 and beginning play in 1999, the club plays in the Eastern Conference of the United Soccer League, the second tier of the American Soccer Pyramid.  Since 2013, the Riverhounds have played their home games at the 3,500-seat Highmark Stadium, a soccer-specific stadium located in Station Square.  Their current head coach is Dave Brandt.  Saint Lucian international David Flavius currently holds the club records for most appearances and goals which he set over his eight seasons with the Riverhounds between 1999 and 2006.  Since December 2015, the Riverhounds have had an affiliate partnership with Columbus Crew SC of Major League Soccer.  In June 2017, the Riverhounds entered into a developmental partnership with the Ocean City Nor'easters of the Premier Development League, the fourth tier of the American Soccer Pyramid, through the 2018 season.

Supporting paragraphs: Columbus Crew SC Gregg Berhalter
Answer: American