The second phase of the German social welfare system spanned the period from 1890, the year of Bismarck's resignation, to 1918. During this period, improvements were made in the initial programs.The National Insurance Code of 1911 integrated the three separate insurance programs into a unified social security system, and compulsory coverage and benefits were extended to white-collar workers. Survivors' pensions for widows were also introduced in 1911. (The many amendments to the National Insurance Code of 1911 were later integrated into the Social Insurance Code of 1988.) In 1916 survivors' benefits were increased, and the retirement age for workers was reduced from seventy to sixty-five. Because its cooperation was needed to maintain production during World War I, the working class acquired more political influence and won greater social protection and representation during this period. Efforts were also made to develop mechanisms for settling labor disputes and organizing voluntary employee committees, issues taken up by new labor legislation and decrees. Most efforts were completed by the mid-1920s.