At the end of 1918, Fore River delivered eighteen ships to Union's six. Post-War and Great Depression The end of World War I did not immediately affect the yard, as it was still producing ships from wartime orders. The only cancellations that occurred in the yard after the war were the cancellation of the Lexington-class battlecruiser . This was offset by the construction of two cruisers, which were delivered in due time. Additionally, the yard finished building the multiple orders that it received for the S-class submarine, as well as orders for two other submarines. Between 1922 and 1925, the yard underwent a major expansion period, including the purchase of the Atlantic Works, which later became Bethlehem Atlantic Works. Bethlehem also purchased a floating drydock from Simpson’s Dry Dock Company, built a battleship slip, and constructed a new way for merchant ships. The terms of the Washington Naval Treaty in 1921 brought the conversion of the Lexington to an aircraft carrier (), which was launched in 1925 in front of a group of over 20,000 people. The treaty brought about the cancellation of , part of the now-prohibited South Dakota-class battleship. The hull was eventually scrapped in 1923 with only 11% of the ship completed. The post-war lull brought about new opportunities for the yard, as it converted or upgraded ships such as , and overhauled locomotives for the New York, New Haven and Hartford Railroad. The yard produced brass fittings for banjo clocks, in an attempt by Charles Schwab to keep the talented workers employed. Eventually, this lull ended in 1925 with the order of a ferry for the City of Boston. Around this time, the yard received orders for and , both the lead ships of their respective classes. At the end of 1925, the yard had built 400 ships, 111 of which were military contracts, while the other 289 were for civilian organizations. Furthermore, the yard built the liners , and for the Oceanic Steamship Company. The Great Depression brought little work to the yard, with the exception of the completion of and . was built from 1936 to 1940, in addition to a handful of destroyers. Employment in the yard dropped drastically during this time, from 4,900 in 1931 to 812 two years later. World War II The Naval Act of 1938 brought increased shipbuilding to the yard, as it mandated a 20% increase in the