The image is one of a series taken by South Australian photographer Samuel White Sweet of the bridge constructed at Murray Bridge (Edwards Crossing) in the 1870s, and its workforce.

After careers as a sea captain and surveyor, Samuel White Sweet (1825-1886) established himself in Adelaide as a well known photographer. 'With his horse-drawn dark room he travelled through South Australia taking hundreds of skilful pictures of the outback, stations and homesteads. The colony's foremost documentary photographer of the 1870s, in the early 1880s he was one of the first to use the new dry-plate process.' (Allan Sierp, 'Sweet, Samuel White (1825–1886)', Australian Dictionary of Biography, National Centre of Biography, Australian National University, http://adb.anu.edu.au/biography/sweet-samuel-white-4678/text7739, published first in hardcopy 1976, accessed online 5 June 2019.) After his death in 1886, his wife continued his gallery in Adelaide Arcade and sold prints made from his glass plate negatives (https://www.daao.org.au/bio/samuel-white-sweet/biography/).

The State Library of South Australia holds a substantial collection of Sweet's photography. Its SA Memory website gives the following account of the bridge's history (https://www.samemory.sa.gov.au/site/page.cfm?u=1206) :

Crossing the River Murray was always difficult. Early explorers such as Hume and Hovell, then Charles Sturt, and various overlanding parties all faced this problem. They generally converted their drays to temporary punts in order to cross. Punts or ferries were used at many points along the river, and still are today. As traffic across the river increased, so did the need for bridges.

In 1864 it was proposed that a bridge be built across the River Murray in South Australia. The decision was driven by growing trade with the South East of the colony and later with Melbourne. The movement of stock to and from the rich grazing lands in the South East was impeded by the river. Animals were lost at considerable cost to their owners. It was decided by a parliamentary Select Committee to build a bridge at Edwards Crossing. The Government Surveyor took depth soundings at various suggested locations including Wellington where a ferry still operates today. Edwards Crossing was selected because the estimated costs for a bridge were cheapest there.

A Warren girder bridge costing 9500 pounds was ordered from England in September 1866 and arrived in early 1868. It went into storage at Dry Creek while debate over the site continued for many more years. Construction of the first South Australian bridge over the River Murray finally began in 1873.

As only the bridge span had been ordered from England, the costs of bridge foundations, supports and approaches had not been accounted for and so the construction budget had blown out before work even began. A year later the engineer was advised that this road bridge would in future have to also carry a railway as part of the inter-colonial network. Despite this and other difficulties, construction was finally completed in March 1879 at a cost of 130 thousand pounds. Bridge traffic had a speed limit of 25 miles per hour (40 kph). From 1886 it carried the railway as well. Road traffic stopped when a train was crossing.

Edwards Crossing became the town of Murray Bridge in 1924. The increasing weight of railway rolling stock meant that a separate rail bridge had to be built. This was completed in 1925. Road traffic continued to use the original bridge. In 1979 a new road bridge was built five kilometres downstream at Swanport, linking to the South Eastern Freeway through the Adelaide Hills.