The William H. Block Company was founded by Herman Wilhelm Bloch who immigrated from Austro-Hungary in 1874 and had Americanized his name to William H. Block, with the opening of a retail store located at 9 East Washington Street in Indianapolis in 1896. The company was also self identified as The Wm. H. Block Co., and Block's.
In 1910, a new eight-story store was constructed on the corner of Illinois and Market Streets. Mr. Block was active in the business until his death in 1928 when the management of the company was passed to his three sons: M. S. Block, R. C. Block, and E. A. Block. The store was expanded to nearly double in size in 1934. The architect for the 1934 expansion was Kurt Vonnegut, the father of writer Kurt Vonnegut, Jr. During the expansion the building's interior and exterior was redesigned in a moderne style, including furnishings, stainless steel escalators, and two-story polished black marble and stainless steel facade entrances. Architectural drawings of the entrances became the trademark logo for the store on gift boxes, print advertisements, and company stationery. A Company publication identified the store as, "one of the country's most beautiful department stores." Restaurants located within the Illinois Street store included the Fountain Luncheonette, the Terrace Tea Room, the Men’s Grille, and the James Whitcomb Riley Room. Block's was the second largest retail company in Indiana, its primary competitor L. S. Ayres & Co. being the larger. Other competitors included H. P. Wasson and Company and L. Strauss & Co.
The Block's store was located across Market Street from the Indianapolis Traction Terminal (the largest traction terminal in the United States). From 1900 to the 1930s, the Indiana interurban system brought shoppers by the thousands from smaller central Indiana towns who wished to shop in downtown Indianapolis. The availability of cheap mass transit to downtown Indianapolis greatly increased the customer base from which the Indianapolis department stores were able to draw. Block's, being directly across the street from the traction terminal, was the first department store shoppers would visit. Block's main competitors were located at least a block away on Washington Street. Central Indiana was networked with the most extensive interurban system in the United States. Most small towns were either on the system or a station was located near by. Interurbans from Indianapolis reached as far as Dayton, Ohio, and Fort Wayne, Indiana. The net result of the interurban system to Block's and its competitors was a customer base that rivaled that of much larger midwestern and eastern cities, such as Detroit, St. Louis and Cleveland.
In 1954, a small branch store was opened in the Indianapolis neighborhood of Broad Ripple; this location was replaced with a full service department store with the construction of the nearby Glendale Shopping Center in 1958.
The William H. Block Co. merged with Allied Stores in 1962. In 1987, Block's was sold to Federated Department Stores at which time the Block's name was discontinued and many store locations were rebranded as Lazarus department stores.
Lazarus closed the downtown Illinois Street store in 1993. In 2003, the Illinois Street store building's upper seven floors were converted into residential apartments and the ground floor remained retail; the building complex is called The Block.