Eads Bridge

FACTSFact sheet

01The man who walked on the river bottom

James Buchanan Eads was born in 1820, in Lawrenceburg, Indiana, and arrived in St. Louis at 13, penniless. He worked as a store clerk and, according to the National Park Service, read in his employer's library. The Mississippi of that era was a graveyard of steamboats: sunken logs, sandbars and exploding boilers sent boats down with their entire cargo.

At 22, Eads fitted out a double-hulled salvage boat and a diving bell improvised from a 40-gallon whiskey barrel, with a hose through which air was pumped from the surface. He went down to the riverbed and walked in the mud, against the current, to tie up the cargo from wrecks. He made a fortune from it and, in the Civil War, built ironclad gunboats for the Union on the western rivers. When the St. Louis bridge came back onto the agenda after the war, nobody knew that river bottom as he did.

02A bridge the engineers rejected

The problem was bigger than the width of the river. The rivermen wanted a wide central span, a clearance of 50 feet above high water and no scaffolding getting in the way of navigation during construction. According to the National Park Service, a Chicago builder, Lucius Boomer, had obtained from Illinois the exclusive right to build the bridge with no intention of building it, only to hold St. Louis back.

Eads presented a design that broke with what was being done: instead of a truss or a suspension bridge, three arches of more than 150 meters, with steel ribs, a metal that until then had not been the main one in any large structure. According to American Heritage magazine, the engineer J. H. Linville, of Philadelphia, called in to assess the design, refused to sign off on it and called it unsafe and impracticable. Eads kept the design and was appointed chief engineer in 1867.

03Down to bedrock, in compressed air

Eads believed the foundation was the critical part and that it had to rest on bedrock, below some 80 feet of sand that the current churned up. On the St. Louis side, the abutment was built in a cofferdam, at 47 feet. For the piers in mid-river, he adopted what he had seen on a trip to Europe: the pneumatic caisson, an enormous bottomless box, filled with compressed air to keep the water out, on top of which the pier was raised while men dug underneath.

The east pier caisson measured 82 by 60 feet, had seven air locks and a working chamber 9 feet high. The sand came out through a pump that Eads himself invented, driven by air. Inside, says the National Park Service, by lamplight, the air hissed nonstop and voices came out thin. On 28 February 1870 the caisson reached bedrock, at 93 or 95 feet below the river surface, depending on the source. The abutment on the Illinois side went down even farther, to nearly 40 meters, and was the deepest compressed-air work done up to that time.

04The illness nobody understood

The deeper they went, the greater the pressure, and the men began coming out of the chambers with pain in the belly, in the joints and, later, paralyzed. On 19 March 1870 the first ones died: James Riley dropped dead fifteen minutes after a two-hour shift, and James Moran, a 35-year-old Irishman, died in the hospital the same day. On 21 March, two days later, the physician counted twenty sick men taken to the hospital and five dead. Nobody knew that compressed air dissolved gas into the blood and that a fast ascent released it as bubbles.

Eads called in his physician, Alphonse Jaminet. On 28 February 1870, the day the east pier reached bedrock, Jaminet had gone down to observe the men and, coming up, stopped four times on the ladder; at home, 45 minutes later, he was paralyzed, and it took him a week to recover. He tells his own case in the report he published in 1871. On taking charge, on 31 March 1870, he shortened the shifts according to the pressure, ordered slower decompression and set up a hospital boat. According to a 2004 review in the journal Undersea and Hyperbaric Medicine, there were 11 deaths in the five months before him and 3 in the fourteen months that followed.

How many died in all, the sources do not agree: 14 according to the National Park Service record and the table by engineer C. M. Woodward, from 1881; 15 according to the same service in a 2001 publication; 13 according to American Heritage. The most cited count of the sick is 119. At almost the same time, the Brooklyn Bridge, in New York, was using the same method, and went less deep.

05The steel, and the arch that would not close

Steel was the other risk. Eads specified strength and elasticity with a rigor the suppliers were not used to meeting; in the design drawings, he records the modulus of elasticity he adopted for cast steel, 27 million pounds per square inch, and how much the member would expand with heat. According to American Heritage, Andrew Carnegie, whose Keystone Bridge Company was erecting the superstructure, complained that nothing that satisfied the engineers was good enough for that job. The first steelworks gave up, and the second charged more.

Erection began in 1873, with the arches growing out as cantilevers from each pier, held by cables tied to temporary towers, with nothing resting in the river. In September, when it was time to join the halves of the first arch, the heat had expanded the steel and the pieces would not fit. According to American Heritage, the crew even packed the tubes in ice before resorting to a threaded joint that Eads had foreseen. In the end, the bridge took 2,390 tons of steel and 3,156 of wrought iron: it was the first large structure with steel as its main metal, but not all steel.

06An elephant and fourteen locomotives

St. Louis needed to believe in the bridge. On 14 June 1874, an elephant crossed the deck: it was said the animal would not step onto an unsafe structure. The engineering proof came on 2 July 1874, when 14 locomotives, totaling about 550 tons, ran back and forth over the arches for five hours. On 4 July 1874 the bridge was opened with a cannon salute, a parade and fireworks; according to the National Park Service, 150,000 people watched.

Engineering success did not pay the bill. The railroads boycotted the bridge, the company went into receivership in less than a year and, in 1878, the bridge went to auction for US$2 million, a fraction of what it had cost. Eads moved on to the jetties at the mouth of the Mississippi and, in 1884, received the Albert Medal in London. He died in 1887, in Nassau, in the Bahamas.

07A hundred and fifty years later

The bridge lost its tracks in 1974 and the roadway closed in 1991. In 1993 MetroLink trains returned to the lower deck, and in 2003 cars returned to the upper one. From 2012 to 2016, a US$48 million restoration stripped off the old layers of paint, replaced reinforcing steel and readied the bridge for another 75 years. Today about 300 trains a day cross it.

In 2024 it turned 150, and the Missouri History Museum ran an exhibition on its construction until November 2025. The most recent news is smaller and more prosaic: in August 2026, after a woman driver died in a crash on the deck, FOX 2 St. Louis showed stretches left in the dark, and the city said it had spent US$200,000 fixing lights whose copper wires had been stolen.

MYTHSWhat people say and what the record shows

• What people say

  It was the world's first steel bridge.

  What the record shows

  It was the first large structure with steel as its main metal, according to the National Park Service. But it contains more wrought iron than steel: 3,156 against 2,390 tons. The first all-steel bridge dates from 1879, in Glasgow, in Missouri itself.

• What people say

  It was the first project to use pneumatic caissons.

  What the record shows

  No. Compressed air was already being used for foundations in France and England from the 1840s and 1850s. What the Eads Bridge had were the largest caissons ever made and the deepest compressed-air work in the world at the time.

• What people say

  Caisson disease was discovered at the Brooklyn Bridge.

  What the record shows

  It had already been described in France, and it killed in St. Louis before Brooklyn. The Eads Bridge physician, Alphonse Jaminet, published his report in 1871, including on his own case; the Brooklyn one dates from 1873.

• What people say

  The elephant proved the bridge could hold.

  What the record shows

  The elephant crossed on 14 June 1874 as a demonstration for the public, resting on a popular belief. The load test was the one of 2 July 1874, with 14 locomotives for five hours.

QUESTIONSFrequently asked questions

Next episode · Structure 22 · premieres Mar 04, 2027

Forth Bridge

Firth of Forth, between South Queensferry (Edinburgh) and North Queensferry (Fife), Scotland, United Kingdom · 1882–1890

Carrying trains across a Scottish estuary more than 1.5 km wide, with channels over 60 meters deep, right after another Scottish bridge had fallen in a storm taking a whole train with it, and convincing the public that the new one would not fall.

Read the story →

SOURCESSources

1. National Park Service, National Register of Historic Places Inventory, Nomination Form: Eads Bridge, 1975 — npgallery.nps.gov
2. National Park Service, Jefferson National Expansion Memorial, "James B. Eads and His Amazing Bridge at St. Louis", Museum Gazette, 2001 — npshistory.com
3. Alphonse Jaminet, Physical Effects of Compressed Air… Illinois and St. Louis Bridge, St. Louis, 1871 — archive.org
4. James B. Eads, Illinois and St. Louis Bridge (plates), c. 1880, Smithsonian Libraries — archive.org
5. W. P. Butler, "Caisson disease during the construction of the Eads and Brooklyn Bridges: A review", Undersea and Hyperbaric Medicine 31(4), 2004 — pubmed.ncbi.nlm.nih.gov
6. American Society of Civil Engineers, "Eads Bridge", Historic Civil Engineering Landmark — asce.org
7. "Mr. Eads Spans the Mississippi", American Heritage, vol. 20, no. 5, August 1969 — americanheritage.com
8. David P. Billington and J. Wayman Williams, "James Buchanan Eads (1820–1887)", Missouri Encyclopedia — missouriencyclopedia.org
9. PBS American Experience, "James Eads Timeline" and "St. Louis Bridge Opening and Disasters" — pbs.org
10. Linda Hall Library, Centuries of Civil Engineering, "Missouri Bridges" — lindahall.org
11. Bi-State Development, "Region Celebrates Completion of the Rehabilitation of the Historic Eads Bridge", 2016 — bistatedev.org
12. The Waterways Journal, "Eads Bridge Remains An Engineering Marvel", 2024 — waterwaysjournal.net
13. FOX 2 St. Louis, "Drivers question Eads Bridge safety after fatal accident", August 2026 — fox2now.com
14. Federal Reserve Bank of Minneapolis, Consumer Price Index, 1800– — minneapolisfed.org

Images

• Fig. 01 — The bridge in February 2025, seen from the St. Louis bank, with a MetroLink train on the lower deck and ice on the Mississippi: Antony-22 · CC BY-SA 4.0
• Fig. 02 — The east pier in 1870, rising on top of the pneumatic caisson that carried it down to bedrock, among the boats and derricks of the works: Autor não identificado (Missouri History Museum) · Public domain
• Fig. 03 — September 1873: the arches grow out as cantilevers from the piers, with no falsework at all in the river: Autor não identificado (Missouri History Museum) · Public domain
• Fig. 04 — The west arch under erection, held by cables to temporary towers, in a plate from C. M. Woodward's 1881 book: C. M. Woodward, A History of the St. Louis Bridge (1881) / Library of Congress · Public domain
• Fig. 05 — The finished bridge, seen from the Illinois side in July 1874, the month of its opening: Robert Benecke (Missouri History Museum) · Public domain