Anti Submarine Escorts were the main deficiency they had none at all.(Along with carriers, they borrowed HMS Victorious from the RN for a while, renamed to USS Robin)
As they had lots of destroyers the plan was to use them as escorts. They quickly found out that they are not good anti submarine escorts. They can't turn tight and have relatively poor anti submarine weapons fit and lack the endurance for escort work
Improving the AS fit meant removing the torpedo fit which took away their main offensive weapon.
Old classes of destroyer were converted to escorts by the RN, they removed the torpedo tubes, reduced the gun mounts and removed boilers to increase fuel capacity and endurance, the reduction in speed wasn't important for an escort. They weren't ideal though and were soon replaced by dedicated escorts.
Luckily the RN had placed big orders for a design of Frigate (Destroyer Escort in US parlance) with US yards. Over a hundred were built for the RN as the Captain Class.
The US Navy decided it eas ideal for their needs and most of the first batch was taken by the US Navy and subsequently hundreds were built.
They were like the Sherman tanks in that there were several sub classes designed to take advantage of different propulsion systems.
There were diesel, diesel electric, steam turbine and turbo electric versions.
The RN influence is obvious in the large anti submarine weapons fit and raised bridge superstructure with an open compass platform bridge above the closed bridge and wheelhouse.
US ships carried torpedoes to give them a limited capability against surface ships. RN ships fitted extra depth charges instead.
US service
RN service
