Here is the Texas State Historical Association’s page on Highland Park:

https://tshaonline.org/handbook/online/articles/hfh03

 

This is a section of that page, with all credit going to TSHA:

In 1913 Highland Park asked Dallas for annexation but was refused. The 500 residents therefore voted to incorporate, on November 29, 1913. The incorporation officially took place in 1915, when the population was 1,100; W. A. Fraser was the first mayor. Highland Park set up its own waterworks, which it operated until 1932. In 1915 the third addition to Highland Park was built, and two years later a fourth. After two years a long annexation controversy began. The city of Dallas regretted its earlier refusal to annex Highland Park and began a battle that lasted until 1945, when Dallas was turned down for the last time. The last major land development in Highland Park, Highland Park West, was built in 1924. In 1931 Highland Park Village, the first shopping center of its type in the United States, was constructed in Highland Park.