The London Bridge in Arizona was designed by John Rennie.
There have been many London bridges. The modern London Bridge built in 1971. It was designed by William Graham Holford, Baron Holford and built by the firm of Mott, Hay and Anderson. John Rennie designed the London Bridge of 1831-1967.
The London Bridge in Arizona was designed by John Rennie and dates from1830 so could be described as an historic monument. The current London Bridge in London England only dates from 1973 so is hardly historic.
Robert Paxton McCulloch bought the London Bridge designed by John Rennie. The bridge was dismantled and moved to Lake Havasu City, Arizona. He bought the bridge for $2.5 million dollars. The bridge cost another $7 million to reassemble. It was opened on October 5, 1971.
John Rennie
The 1831 John Rennie designed bridge was bought and shipped to Arizona it replaced an older bridge (600 years old). The current London Bridge which dates from 1973 is still located in London at the same site where a bridge has stood for 2,000 years.
John Augustus Roebling designed the Brooklyn Bridge, but his son Washington A. Roebling completed the building portion
Rennie's London Bridge.
Much the same as it did when it was in London.
The reconstruction of Rennie's Bridge at Lake Havasu began in 1968 and was completed in 1971.
The original London Bridge was built by the Romans around AD 50. The most famous version, completed in 1209, was constructed by Peter of Colechurch, a priest, and it featured a stone design with houses and shops. Over the centuries, the bridge underwent several renovations and eventually was replaced in the 19th century by a granite bridge designed by John Rennie. The 20th-century bridge that stands today was opened in 1973, built to accommodate modern traffic needs.
If you are referring to the 1830 bridge which is now in Arizona, the engineer was John Rennie.