Lester B. Pearson was easily elected Liberal leader at the party's 1958 leadership convention. However, only months after becoming Liberal leader, Pearson led the party into the 1958 federal election that saw Diefenbaker's Progressive Conservatives win the largest majority government, by percentage of seats, in Canadian history. The Progressive Conservatives won 206 of the 265 seats in the House of Commons, while the Liberals were reduced to just 48 seats. Pearson remained Liberal leader during this time and in the 1962 election managed to reduce Diefenbaker to a minority government. In the 1963 election Pearson led the Liberal Party back to victory, forming a minority government. Pearson served as Prime Minister for five years, winning a second election in 1965. While Pearson's leadership was considered poor and the Liberal Party never held a majority of the seats in parliament during his premiership, he left office in 1968 with an impressive legacy. Pearson's government introduced Medicare, a new immigration act, the Canada Pension Plan, Canada Student Loans, the Canada Assistance Plan, and adopted the Maple Leaf as Canada's national flag.