Twentieth century.

Historian John Brooks in his book Once in Golconda considered the turn of the 20th century period to have been Wall Street's heyday.^[19] The address of 23 Wall Street where the headquarters of J. P. Morgan & Company, known as The Corner, was "the precise center, geographical as well as metaphorical, of financial America and even of the financial world."^[19]

Wall Street has had changing relationships with government authorities. In 1913, for example, when authorities proposed a $4 tax on stock transfers, stock clerks protested.^[23] At other times, city and state officials have taken steps through tax incentives to encourage financial firms to continue to do business in the city.

In the late 19th and early 20th centuries, the corporate culture of New York was a primary center for the construction of skyscrapers, and was rivaled only by Chicago on the American continent. There were also residential sections, such as the Bowling Green section between Broadway and the Hudson river, and between Vesey Street and the Battery. The Bowling Green area was described as "Wall Street's back yard" with poor people, high infant mortality rates, and the "worst housing conditions in the city."^[24] As a result of the construction, looking at New York City from the east, one can see two distinct clumps of tall buildings—the financial district on the left, and the taller midtown district on the right. The geology of Manhattan is well-suited for tall buildings, with a solid mass of bedrock underneath Manhattan providing a firm foundation for tall buildings. Skyscrapers are expensive to build, but when there is a "short supply of land" in a "desirable location", then building upwards makes sound financial sense.^[25] A post office was built at 60 Wall Street in 1905.^[26] During the World War I years, occasionally there were fund-raising efforts for projects such as the National Guard.^[27]

On September 16, 1920, close to the corner of Wall and Broad Street, the busiest corner of the financial district and across the offices of the Morgan Bank, a powerful bomb exploded. It killed 38 and seriously injured 143 people.^[28] The perpetrators were never identified or apprehended. The explosion did, however, help fuel the Red Scare that was underway at the time. A report from the New York Times:

“

The tomb-like silence that settles over Wall Street and lower Broadway with the coming of night and the suspension of business was entirely changed last night as hundreds of men worked under the glare of searchlights to repair the damage to skyscrapers that were lighted up from top to bottom. ... The Assay Office, nearest the point of explosion, naturally suffered the most. The front was pierced in fifty places where the cast iron slugs, which were of the material used for window weights, were thrown against it. Each slug penetrated the stone an inch or two and chipped off pieces ranging from three inches to a foot in diameter. The ornamental iron grill work protecting each window was broken or shattered. ... the Assay Office was a wreck. ... It was as though some gigantic force had overturned the building and then placed it upright again, leaving the framework uninjured but scrambling everything inside. -- 1920[29]

”

The area was subjected to numerous threats; one bomb threat in 1921 led to detectives sealing off the area to "prevent a repetition of the Wall Street bomb explosion."^[30]