According to the RPI Union Constitution, Article 5, section 2, "The Grand Marshal shall be the presiding officer of the Student Senate and an ex officio member of all committees. The Grand Marshal shall be regarded as the leader and the chief spokesperson for the entire Union and shall be a nonvoting member of the Student Senate. In the event of a tie, the Grand Marshal may cast one vote. Any appointments made by the Grand Marshal may be nullified by a majority vote of the entire Student Senate membership." 
The position of Grand Marshal was created in 1866 to honor a student respected and admired by his classmates. Major Albert Metcalf Harper of Delta Phi was elected and presented a ceremonial sword, as was fitting for a Major during the Civil War. His function was to head and represent the entire student body on all occasions in all relations, thereby giving it a formal unity. Except for a few years during the 1890s Grand Marshals were elected each year, usually in the spring, and this provided, as it were, the culminating event of the student calendar with celebrations of the Grand Marshal's election and installation.
The election customs were well established by 1882, when Independence Grove, a strangely named junior, of Chi Phi, was elected Grand Marshal. In 1883 occurred a characteristic Grand Marshal's election night on May 26. William A. Aycrigg was chosen without opposition in Harmony Hall, used for many years for the purpose, and the retiring marshal was presented with a suitably inscribed gold-headed cane. The students then filed into the streets and, headed by Doring's Band, paraded through the city, with Greek fire displays and houses illuminated. They stopped at Boughton's hat store, where the new marshal was presented with a high silk hat, still used symbolically as the headgear of the office.
A common practice of the student parade was to serenade the students of the Emma Willard School, located in downtown, as well as some of the professors and school dignitaries at their homes, and they generally responded with speeches of acknowledgment. At about eleven at night the parade returned to Harmony Hall for food, drink and dancing. Until the wee hours of the morning, the press reported, the shouts and plaudits could be heard for blocks on the still night air. In 1883 the total expenses of the election were $212.50, raised by class assessments, and they included $28 for the hall and damages to it, $127 for the music, and $12 for the services of the 8 policemen at the hall.
Today, a special committee plans the "GM week" events, which occur on the last week of March. The week kicks off with events in the Armory; in the past these have included twister, miniature golf, rock climbing, a pie eating contests, and laser tag. Then there are dozens of events each day of the week, hosted by various clubs and fraternities. Events usually include battle of the bands style concerts, tennis and volleyball tournaments, fireworks, and engineering contests such as an egg drop competition from the top of the JEC. At the end of the week, the final induction ceremony is often held in the Houston Field House.