Too poor to attend college, Lawrence instead took a job as a clerk for Pittsburgh attorney William Brennan, the chairman of the local Democratic party and a labor movement pioneer.

At the time, Pittsburgh was a Republican bastion, with Democrats holding wide support only in the lower class and among recent immigrants, who were concentrated in industrial jobs.

With the help of Joe Guffey, a future US Senator, Lawrence led the rising Pennsylvania Democratic party that would soon dominate local and statewide politics.

In the 1928 presidential election, Lawrence worked hard for Alfred E. Smith from New York, another Irish Roman Catholic politician who had also risen from the slums without the benefit of a formal education.

[7] Consequently, at the 1932 Democratic National Convention, Lawrence deserted Al Smith's presidential campaign and delivered the Pennsylvania delegation to Franklin D. Roosevelt, solely because of his fear of the religious issue.

Lawrence developed a seven-point program for Pittsburgh during his first days in office, making him one of the first civic leaders to implement a dedicated urban renewal plan.

[8] A 1993 survey of historians, political scientists and urban experts conducted by Melvin G. Holli saw Lawrence ranked as the third-best American big-city mayor to serve between the years 1820 and 1993.

In the weeks leading up to the 1948 Democratic National Convention, Lawrence was one of the few urban bosses to support Harry S Truman's attempts to win the Presidential nomination.

[10] Lawrence is often credited with convincing John F. Kennedy to choose Lyndon Johnson as his running mate to balance the ticket and mend a rift between northern and southern Democrats.

He continued to be active in Democratic politics and served the Kennedy and Johnson administrations as Chairman of the President's Committee on Equal Opportunities in Housing.

[14] Lawrence fell ill and collapsed on November 4, 1966, at a campaign rally held at Pittsburgh's Syria Mosque for gubernatorial candidate Milton Shapp.

The 2,000 attendees included Senator Robert F. Kennedy, Mayors Joseph M. Barr of Pittsburgh, Jerome Cavanagh of Detroit, James Tate and Richardson Dilworth of Philadelphia, Govs.

[22] Lawrence's two eldest sons both died as passengers in a joyriding car accident on April 19, 1942, north of Pittsburgh near Zelienople along U.S. Route 19.

[23] Another son, Gerald Lawrence, became the long-time Vice President and General Manager of Churchill Downs, the prominent racetrack in Louisville, Kentucky.