itself, for the entire 19th century. At the beginning of the century, this role was far from secure after the strong growth in world commerce during the later decades of the 18th century rendered the overcrowded Pool of London incapable of handling shipping levels efficiently. Sailors could wait a week or more to offload their cargoes, which left the ships vulnerable to theft and enabled widespread evasion of import duties. Losses on imports alone from theft were estimated at £500,000 per year in the 1790s – estimates for the losses on exports have never been made. Anxious West Indian traders combined to fund a private police force to patrol Thames shipping in 1798, under the direction of magistrate Patrick Colquhoun and Master Mariner John Harriott. This Marine Police Force, regarded as the first modern police force in England, was a success at apprehending would-be thieves, and in 1800 it was made a public force via the Depredations on the Thames Act 1800. In 1839 the force would be absorbed into and become the Thames Division of the Metropolitan Police. In addition to theft, at the turn of the century commercial interests feared the competition from rising English ports like Liverpool and Plymouth. This spurred Parliament in 1799 to authorize the first major dock construction work of the 19th century, the West India Docks, on the Isle of Dogs. Situated 6 miles east of London Bridge, shipping could avoid the dangerous and congested upper reaches of the Thames. The three West India Docks were self-contained and accessed from the river via a system of locks and basins, offering an unprecedented level of security. The new warehouses surrounding the docks could accommodate close to a million tons of storage, with the Import and Export basins able to moor almost 400 ships at a time. The Commercial Road was built in 1803 as a conduit for newly arrived goods from the Isle of Dogs straight into the City of London, and in 1812 an Act of Parliament provided for the docks to be integrated into the national canal system via the extension of the Grand Union Canal to Limehouse. The Regent's Canal, as this new branch between Paddington and Limehouse became known, was the only canal link to the Thames, connecting a vital shipping outlet with the great industrial cities of The Midlands. The Regent's Canal became a huge success, but on a