The Union has a very rich history in Indianapolis. It was designed to provide training in such fields as mechanics, drafting, and the domestic arts. On June 14, 1888, the board went on record as favoring the proposed step of manual training education and voted to establish two such classes in the Indianapolis High School. Forty students enrolled in these first classes, and enthusiasm for the undertaking grew. A bill enabling the Board of School Commissioners to levy a tax for the construction of an industrial school in Indianapolis was introduced in the Indiana House of Representatives on February 19, 1891. This bill, permitting the collection of five cents on every hundred dollars of taxable property in Indianapolis for the establishment of an industrial training school, was passed with one dissenting vote, on March 7, 1891.

Although several sites were considered, the south side was favored because there was no high school already in that area. In 1894, school authorities purchased a tract of land for $40,000. Dedication ceremonies for the Industrial Training School at 525 South Meridian Street in Indianapolis took place on May 31, 1895.

In 1899, the school was renamed Manual Training School. In 1916, it was renamed Charles E. Emmerich Manual Training High School, in honor of the first principal of the Industrial Training High School.

On June 7, 1920, the cornerstone of the "South Building" extension was laid. This would include an auditorium, cafeteria, and new gymnasium. A portion of this wing collapsed while under construction in November 1920. The addition opened in the Spring of 1922.

In 1953, the Charles E. Emmerich Manual Training High School relocated to 2405 Madison Avenue, its present location. The Meridian Street facility was renamed the Harry E. Wood Vocational Training School.

Harry E. Wood High School opened in the fall of 1953 with the specific purpose of providing vocational education at the secondary level. Indianapolis Public Schools refurbished the old building with an extensive $350,000 renovation.

While vocational training was the original purpose of Wood High School, the school board decided that the primary focus would be on academics, but with exceptional facilities and curriculum to provide students with the vocational training they would need to be successful after high school.

The new school was named for Harry E. Wood, who was an alumni of Manual High School. He became an renowned artist and craftsman, and was an educator and administrator at Manual. He also lectured at many universities and was president of several art associations. Wood retired from IPS in 1950 and died in 1951.

In athletics, Indianapolis Wood High School won several Sectional Championships in both basketball & track. The Woodchuck's wrestling team won the Indiana State Championship in back-to-back seasons, 1959-60 & 1960-61. Former Harlem Globetrotter, "Jumpin' Johhny" Wilson became the first black head coach of an integrated Indiana high school when he was named head basketball coach at Wood. Wood High School was closed in 1978. In 1981, IPS sold off the buildings and parking lots.

In 1984, Brougher Insurance Group purchased the building and converted the old school house into an office building. In early 1999 the building was sold again, but this time to Lilly. It was remodeled again and Lilly occupied the space in early 2000.

In 2015, a group of investors purchased the building from Lilly with the intent to do something big, and out of that commitment, The Union was born. The first tenants took possession of the property on December 1, 2016, and thus a new era of innovation began.