Before construction of the Longhorn Dam was completed in 1960, the bridge crossed the Colorado River from which Lady Bird Lake is impounded.

Bridge construction was finished at a cost of $80,000; an additional $20,000 was used to macadamize dykes across lowlands and a culvert over Bouldin Branch.

[1] On November 16, 2006, the Austin City Council renamed the structure the Ann W. Richards Congress Avenue Bridge at its weekly meeting.

In March 1986, Merlin Tuttle, founder of Bat Conservation International, resigned from his position as Curator of Mammals at the Milwaukee Public Museum in Wisconsin and relocated his fledgling conservation organization to Austin, which had been making national headline news for its urban bat population.

[6] Tuttle's public education campaign to save the bats through dispelling myths and misconceptions about their threats to the citizens of Austin was met with widespread skepticism and earned him the 1986 Texas Monthly Bum Steer Award.

[7] However, with help from a coalition of leaders in the Austin community, the Public Health Department, and news media, Tuttle's persistent education efforts successfully reversed public opinion about the bats and turned the Congress Avenue Bridge bat colony into the highly profitable tourist attraction for the city of Austin that it is today.

[8] The nightly emergence of the bats from underneath the bridge at dusk, and their flight across Lady Bird Lake primarily to the east, to feed themselves, attract as many as 100,000 tourists annually.

A study made in 1999 by Gail R. Ryser and Roxana Popovici concludes that the economic impact of the bats to Austin city is $7.9 million each year.

[citation needed] Ozzy Osbourne features the Congress bridge bats in his music video for Patient Number 9.