The "999 train" refers to the New York Central Railroad's locomotive No. 999, a steam engine built in 1893. The engine was equipped with a 4-4-0 wheel arrangement which showcased its capabilities. On May 10, 1893, the 999 became the fastest land vehicle when it reached a record speed of 112.5 mph, a record maintained for a decade. This milestone demonstrated the rapid advancements of steam locomotives in this time period. Designed by William Buchanan and manufactured by the New York Central Railroad in West Albany, New York in 1893, the 999 was commissioned to haul the Empire State Express, which ran from Syracuse to Buffalo. This relatively smooth run and the 999's cutting-edge design gave the new locomotive an opportunity to make history.

Following its record-setting run, "The World's Fastest Locomotive" toured the country and was displayed at the 1893 World's Columbian Exposition in Chicago. After the Exposition, the 999 continued to provide passenger and freight service for many years. The famous locomotive returned to Chicago in 1933 for the Century of Progress World's Fair and again from 1948-49 for the Chicago Railroad Fair. In May of 1952, the 999 was retired from service. The historical significance of the 999 train lies in its role in advancing locomotive technology and its impact on the railroad industry. It transformed transportation and facilitated the movement of people, supplies, and products across great distances more efficiently than ever before. The 999 train not only symbolizes major advancements in transportation, it also marked the beginning of a new era of speed in land travel, significantly impacting modern technology, the economy, and society.