The 50 destroyers of the 'Town' class, as they were known in the RN, have a fairly complicated legacy. They joined the RN at a time of significant crisis and represented one of the first tangible examples of American support for the Allied cause. However, they were largely obsolete, with the refits required to bring them to the RN's standards meaning that they missed the worst depths of the crisis. They also suffered from frequent problems due to their age.

On the 15th May 1940, with the German offensive in France and the Low Countries in full swing, Churchill requested from Roosevelt a short-term loan of 'forty or fifty of your oldest destroyers'. These ships were intended to fill in the gap between the present moment and the commissioning of the new escorts laid down for the RN around the start of the war. Over the next few months, Churchill kept up this pressure. Ultimately, Roosevelt was able to negotiate an agreement which he could get past isolationist elements in Congress. In selling the deal, he emphasised the fact that the ships were 'on their last legs', and had a scrap value of about $5000. In return for the fifty ships, the US received basing rights in a wide variety of British possessions in the Carribbean, in Bermuda and in Newfoundland.

The deal was signed on the 3rd September 1940. Three days later, the first batch of eight destroyers arrived at the Canadian port of Halifax in Nova Scotia. The same day, their future British crews arrived at the port in the liner Duchess of Richmond. Over the next two days, the American crews who had brought the ships to Halifax walked the British crews through the working of the destroyers. The British also inspected the ships here, to determine what would need fixing in their initial refit before entering service proper. On the 9th, the first batch would be commissioned into the Royal Navy. The remainder of the 50 would follow a similar process over the next few months; six would go to the Royal Canadian Navy, with the other 36 going to the RN.

On receiving the ships, the RN felt they needed fairly significant upgrades. Their auxiliary machinery (i.e pumps, winches, generators etc) was obsolete and needed replacing. Their plumbing and wiring had degraded over the time spent in reserve, and needed major repairs and upgrades. Their AA armament was heavily lacking, having been designed before aircraft posed a major threat. There were also issues that came from doctrinal or design differences between British and American practice. American ships were designed with a lower enclosed bridge. The British felt that this restricted the view from the bridge too much, a significant failing for an escort given that many submarine contacts, especially at night, were made using the naked eye in the days before widespread radars. The RN was also not a fan of their primary armaments, with the American 4" gun's ammunition being seen as too fragile, while their torpedo armament was believed to be unreliable and have poor depth-keeping. To fix these issues, the ships were taken into British dockyards, mainly Devonport, for long refits. During these refits, a new open bridge was built on top of the existing bridge structure. The forefunnel was raised, to keep smoke off the new bridge. Their gun armament was removed, with the exception of the bow gun, with a British 12pdr gun being added aft. Several light AA mounts were added, typically two quadruple mounts for the British .50cal machine gun and four single .303 MGs. The after sets of torpedo tubes were removed and replaced with depth-charge throwers. To maintain their stability, the masts were cut down, with the mainmast being removed completely, and new ballast added. Later refits added more light AA, radar and ultimately the Hedgehog ahead-throwing anti-submarine weapon. The last pair of torpedo tubes were replaced with a single centreline tube. Three of the RN ships and two of the RCN ships would be upgraded to long-range escorts, with boilers removed to free up space for additonal fuel. The last vestiges of their American armament was removed and replaced with British equivalents, and they were given enough depth-charge throwers and rails for a fourteen-charge pattern. The British ships also received a rebuilt bridge structure, following the pattern used on existing British destroyers.

The ships started to leave refit and enter service in early 1941 - with one exception, HMS Cameron, bombed and burned out while under refit in Portsmouth. They were not significant successes. The long period in reserve had led to corrosion of rivets along their sides. This allowed for seawater to leak into the fuel tanks. While their machinery was generally reliable, contamination of the fuel with seawater led to a loss of efficiency at best, and a complete loss of power at worst. Their steering system, which was not replaced in the refits, was also hopelessly obsolete. It used long chains or wires to connect the ship's wheel to the rudder. These had a tendency to jam or break, which when combined with the ships' large turning circles (twice that of comparable British ships) led to a high rate of collisions. They were poorly suited for service on the North Atlantic convoy routes. They had no forecastle and low freeboard forwards, which meant they often had waves break over their bows. As there was a large hatch for access to the crew's mess decks forward of the bow gun, this could lead to flooding. Their bridge structures and funnels were also liable to damage from the weather, especially since the bridge was too far forward and, as originally built, too fragile. They had fine, narrow sterns, which reduced the space available for depth charges. It also left their propellers exposed and easily damaged in collisions. Their narrow hulls also meant they tended to roll badly in poor weather, which was bad for their crews. All of these issues added up to a lot of time spent in repair or refit.

The reception of the ships was mixed. On a strategic level, they were significant. They were one of the first, direct examples of American support for Britain. At a time when the British Empire seemed to be standing alone, this gesture was a major morale boost. However, the Royal Navy was largely less enthusiastic about the ships, except in hindsight. George Creasy, the RN's director of anti-submarine warfare in 1940-41, described them as 'an appalling headache to keep running'. The anti-submarine ace Donald Macintyre described them as 'vile little ships'. Admiral Tovey felt that they were the worst destroyers he had encountered, 'poor seaboats with appalling armament and accommodation'. It was only looking back, with the popular perception that the ships were filling an important gap in the RN's capabilities in the autumn of 1940, that views of them became more favourable. However, this was not the case - the need for extensive refits before they could enter service meant that more modern British escorts were becoming available in significant numbers by the time they were ready.