Confederate forces acquired hundreds of Clyde-built boats because they were fast, making them ideal for evading Union ships blockading Southern ports.
Archaeologists believe the shipwreck off Oak Island, North Carolina, is a blockade runner called Agnes E Fry.
It was launched on the Clyde under a different name, Fox.
A sonar scan was made of the wreck earlier this year and the shape, size and location suggests that it is of the Agnes E Fry.
Deputy state archaeologist, Billy Ray Morris, told the BBC News Scotland website that a further investigation was imminent.
He said: "We will be conducting 3D sonar imaging operations on Fry next week and will have a detailed computer model of the site shortly thereafter."
The North Carolina archaeologist added: "Agnes E Fry was built by Caird & Co in Greenock. She was launched 26 March 1864.
"She was an iron-hulled paddle steamer with two oscillating engines. She was lost 27 December 1864 commanded by Joseph Fry.
"Originally named Fox, Fry renamed her after his wife when he took command."
Coincidently, work is also under way to try and give a wrecked blockade runner in Scottish waters better protection.
The Iona I operated on a Glasgow to the Highlands passenger route before it was purchased by Confederate agents for use in delivering supplies to blockaded American ports.
But it never reached the war as it sank in the Clyde near Gourock following a collision with another ship in 1862.
Earlier this year, the Scottish government proposed designating the site as a Historic Marine Protected Area (HMPA) to preserve it as a historic asset of national importance.
Historic Environment Scotland has begun a public consultation on the designation.
The wreck of Iona I has been described as being in a good condition. Glasgow Museums has a scale model of the paddle streamer in its collections.

Natalia Doherty was last seen on 15 April 2003 in Eastbourne, where she was living at the time.
The house in Icknield Way was searched in September as part of the investigation.
Two men were later arrested and bailed in connection with the disappearance.
A Luton man, aged 66, and a 71-year-old man from Port Glasgow, Inverclyde, were detained on suspicion of assisting an offender and preventing a lawful burial.
Officers said ground survey work was now being carried out on the surface of the garden to see if the ground had been disturbed.
Detectives believe that near to the date she was last seen alive, Ms Doherty - who was also known by the surnames Wilkanowska and Logan - was thought to have travelled to Luton to stay with her ex-husband, Gerald Doherty, who has since died - at the Regents Arms in Hastings Street.
But there were no confirmed sightings of the mother-of-three in the town.
Officers from the Bedfordshire, Cambridgeshire and Hertfordshire major crime unit launched an investigation in January 2014 into the case, which has led them to believe Ms Doherty was murdered.
A police spokesman said: "Inquiries have since failed to show any sign she is alive."
Investigators are keen to trace her final movements and has asked anyone who recognises her or Mr Doherty from their time at the now-demolished pub in Hastings Street, or has any information relating to her disappearance, to contact them.
Archaeologists are preparing to make a detailed examination of a wreck believed to be that of a Scottish ship used in the American Civil War.
[NEXT_CONCEPT]
A garden at a property in Luton is being examined by officers investigating the disappearance of a 50-year-old woman police now believe was murdered.