The Dow Jones Industrial Average's lowest closing value during the 1929–1932 collapse was 41.22.
The Dow reached that closing low on July 8, 1932, after falling from its pre-crash closing high of 381.17 on September 3, 1929. The decline represented a loss of almost 89 percent and occurred amid bank failures, deflation, falling production, and mass unemployment during the Great Depression.
The 1929 crash itself was not a single day's event. Although October 1929 brought spectacular selling, the market continued falling for nearly three years. That extended decline is why historians distinguish the Wall Street Crash from the broader financial and economic catastrophe of the Great Depression.
The figure 28.48 is associated with the Dow's intraday low on July 8, 1932, not its closing value. The index recovered gradually, but it did not regain its September 1929 closing high until 1954.