Alexander, who grew up in Lebanon , New Hampshire , started ski jumping in 1999 at the age of 10. Shortly thereafter, he received a scholarship to the National Sports Academy in Lake Placid . In 2007 he was accepted into the team for the FIS Cup . On December 1, 2007, he made his debut in the Ski Jumping Continental Cup in Pragelato . In his first season, however, he remained without points. At the Junior World Championships 2008 in Zakopane he reached the 56th place in individual and 8th place with the team in team jumping. In the 2008/09 Continental Cup season he was able to jump into the top ten for the first time with eighth place in Pragelato and in the end achieved 81st place in the overall standings with 60 points. At the US Championships in Park City in 2008 , he won the bronze medal in individual jumping. In March 2009 he was nominated for a World Cup jumping for the first time. In the individual, however, he failed with the 47th place in the qualification. In team flying, he and the team ended up in twelfth place. At the Summer Grand Prix 2009 in Courchevel he was able to draw attention again with 15th place. On November 28, 2009 he then succeeded in the Finnish Kuusamo for the first time the qualification for the main field of a World Cup, where he missed the leap into the points as 44th. At the 2010 Winter Olympics in Vancouver , Alexander retired from jumping on the normal hill as 41st and from the large hill as 40th after the first round. With the team he reached eleventh place in the team competition.
On January 26, 2013, Alexander was able to achieve his best position in this competition so far as third in the Continental Cup jumping in Titisee-Neustadt .
At the 2014 Winter Olympics in Sochi , he was eliminated in the individual competitions as 35th on the normal hill and 48th on the large hill after the first round. With the US team he was tenth.
On September 14, 2014 Alexander won the FIS Cup jumping in Planica ahead of Anže Semenič and Stefan Huber and thus achieved his only international victory in an FIS competition. On February 1, 2015, he was the 27th to get his only four World Cup points of his career on the Mühlenkopfschanze in Willingen . He finished the 2014/15 season as 78th in the overall World Cup . In February 2015, he took part in the Nordic World Ski Championships for the first time in Falun . In the individual competition on the normal hill he failed as 41st in the qualification and in the mixed team competition he finished seventh with the US team.