Around 1898, The Fort Worth Telephone Co. constructed a new building on the northeast corner of 11th and Throckmorton. This was a competing company with Southwestern Bell. In 1905, Southwestern Bell Telephone constructed a three story building on the southeast corner of 10th and Throckmorton Streets. It was known as the Lamar Office. The phone company expanded rapidly and in 1914, a one story addition was constructed to the south side of the building, and two floors were added on top. In 1916, the company purchased a vacant lot to the south and the Fort Worth Telephone Co. A one story operator’s school building was built on the vacant lot in 1918. By 1920, the Lamar Building was expanded again by constructing a 2nd and 3rd floor to the elevator wing on the south side of the building. In 1926, the Fort Worth Telephone and Operator’s School buildings were demolished to construct a three story building that housed the “2-3” step-by-step dial system office and the new division office. It was designed to be expanded to eight stories. This building still stands today on the northeast corner of 11th and Throckmorton, although it has been added on both vertically and horizontally and the facade has been altered to match the entire complex. In 1929, the company added three floors to the “2-3” building. In 1949, another 4 story building was built between the structures on Throckmorton, giving the telephone company the entire block frontage. In 1958, a 9 story addition was constructed along Houston Street, stretching across the entire block. This addition was originally designed for sixteen floors. By 1965, the Houston Street building was expanded by two floors and the 1926 and 1949 buildings had 2 and 4 floors added, respectively.