Until the latter years of the eighteenth century one had to employ the services of the ferry in order to cross the Foyle at Londonderry. The ferry rights were held by the City Corporation from the Society of the Governors and Assistants, London, of the New Plantation of Ulster, (The Hon. The Irish Society), at a rent of £20 per annum. The Corporation sublet their right to operate the ferry for an annual sum of £300.
As early as 1769 the Corporation of Londonderry was petitioning The Hon. The Irish Society for permission to construct a bridge across the River Foyle, but it was not until 1786 that consent was forthcoming.
The contractor for the bridge was one Lemuel Cox from the firm of Cox & Thompson, Boston, New England hence the reason for it being referred to as, "the Boston Bridge." Construction of the 1068 feet long structure commenced in 1789 and foot passengers were able to use the bridge by the end of 1790, although it would be 1791 before carts and other vehicles were able to cross It. The oak piles for the bridge are reported as having been imported from America. Twenty workmen travelled with them to assist in the construction. The bridge was lit by gas and it originally incorporated a short drawbridge which was subsequently replaced by a turning bridge so as to allow river traffic to proceed up to Strabane. Throughout its existence the wooden Boston Bridge was a toll bridge. (It was demolished soon after the opening of its successor, the Carlisle Bridge in 1863). The toll office was on the western side side of the bridge. The cost of the original construction was £16,594. When a 350 feet long portion was swept away by ice in 1814 the repair bill was £18,208.
The bridge over the River Foyle was to be the first of several bridges constructed by Lemuel Cox throughout Ireland including one over the River Suir at Waterford. Between 1792 and 1796 Cox along with his wife and two of his sons resided in Ireland before returning to America where he died in 1806. Prior to becoming a bridge builder it appears that Cox was a wheelwright.Sources : Dictionary of Irish Architects; Colby's Ordnance Survey and Commemorative Booklet of Visit of The Right Hon The Lord Mayor of London to Londonderry 1933