[1] An extensive network of pedestrian tunnels and skywalks connects a large number of buildings in the district; this system also serves as a subterranean mall.

The district's streets form a strict grid plan of approximately 400 square blocks,[2] oriented at a southwest to northeast angle.

The northern end of the district is crossed by Buffalo Bayou, the banks of which function as a linear park with a grade-separated system of hike-and-bike trails.

[9] By April 1837, Houston featured a dock, commercial district, the capitol building of the Republic of Texas, and an estimated population of 1,500.

The Allens gifted a number of city blocks to prominent Texas politicians and agreed to construct the new capitol building and a large hotel at no cost to the government.

[8] The Allens also donated blocks to celebrities, relatives, prominent lawyers, and other influential people in order to attract additional investment and speculation to the town.

[8] During the late 1830s and early 1840s, Houston was in the midst of a land boom, and lots were selling at "enormous prices," according to a visitor to the town in 1837.

[8] Despite the efforts of the Allen brothers and high economic interest in the town, first few years of Houston's existence were plagued by yellow fever epidemics, flooding, searing heat, inadequate infrastructure, and crime.

[12] To the north, along a bend in Buffalo Bayou, the working-class neighborhood of Frost Town welcomed immigrants from Europe and Mexico during the late 19th and early 20th centuries.

One of the first systems, the Houston City Street Railway, opened in 1874 with four lines along the principal commercial thoroughfares in the heart of the business district.

[14] Residential development subsequently moved out of the central business district; Quality Hill was virtually abandoned by the turn of the 20th century.

As interchange connections with the 610 Loop opened, according to Barna Downtown "became just another node in a multi-node grid" and, as of 1998, "has been that, with already established high densities and land prices."

[23] In 1997 Tim Reylea, the vice president of Cushman Realty, said that "None of the major central business districts across the country has seen the suburban-to-downtown shift that Houston has.

[21] The cutbacks by firms such as Dynegy, in addition to the fall of Enron, caused the occupancy rate of Downtown Houston buildings to decrease to 84.1% in 2003 from 97.3% less than two years previously.

[19] In 2004, the real estate firm Cresa Partners stated that the vacancy rate in Downtown Houston's Class A office space was almost 20%.

Developers have invested more than US$4 billion in the first decade of the 21st century to transform Downtown into an active city center with residential housing, a nightlife scene and new transportation.

[30] January 1, 2004, marked the opening of the "new" Main Street, a plaza with many eateries, bars and nightclubs, which brings many visitors to a newly renovated locale.

[32][33] In June 2019 Dianna Wray of Houstonia wrote that Downtown Houston had an increased amount of pedestrian traffic and residents compared to the post-oil bust 1980s.

Downtown Houston was on the threshold of a boom in 1970 with 8.7 million square feet (800,000 m2) of office space planned or under construction and huge projects being launched by real estate developers.

[71] Tim Reylea, the vice president of Cushman Realty, said that the Continental move "is probably the largest corporate relocation in the central business district of Houston ever.

[89] In 2001, Halliburton canceled a move to redevelop land in Westchase to house employees; real estate figures associated with Downtown Houston approved of the news.

[106] The Harris County court system is located within a five block area bounded by Franklin, San Jacinto, Caroline, and Congress Streets.

[117] Joe Kegans Unit, located in Downtown, is a Texas Department of Criminal Justice state jail for men.

These parks tie into the larger civic complex anchored by City Hall and the main branch of Houston Public Library.In the Historic District to the north, Market Square Park occupies a block formerly covered by Houston's open air market which fronted the old City Hall.

The park contains a statue of former President George H. W. Bush, who represented a portion of west Houston during his time in the United States House of Representatives.In the Convention District, Discovery Green, immediately west of the George R. Brown Convention Center, contains an amphitheater, two restaurants, a dog run, a jogging trail, multiple lawns, and an artificial lake on nearly 12 acres (49,000 m2) of land.

[148] Since its opening in 2008, Discovery Green has become one of Downtown's main attractions, hosting approximately 1.2 million visitors a year and serving as one of the city's premier public spaces.

[citation needed] Houston is one of only five cities in the United States with permanent professional resident companies in all of the major performing art disciplines of opera, ballet, music, and theater.

In the mid-2010s, the promenade between the Center and Discovery Green was transformed into Avenida Houston, a mixed-use corridor featuring restaurants and retail spaces.

[179][205] On September 27, 1897, a school in the two-story annex to the Sacred Heart Parish, staffed by Dominican sisters, opened with 28 enrolled students.

[207] The Sacred Heart School provided Catholic elementary education for 70 years until its closing in May 1967 after declining enrollment and increased operation costs.