Labor

4/12/48 NYT Caption: John L. Lewis, head of the United States Mine Workers, called off the four-week soft coal strike today. [...] Senators Styles Bridges reads the Trustees' statement at a press conference at United Mine Workers headquarters. An agreement was reached on the pension problem and Lewis notified soft coal workers to return to their jobs.
"John Llewellyn Lewis (February 12, 1880 – June 11, 1969) was an American leader of organized labor who served as president of the United Mine Workers of America (UMW) from 1920 to 1960. A major player in the history of coal mining, he was the driving force behind the founding of the Congress of Industrial Organizations (CIO), which established the United Steel Workers of America and helped organize millions of other industrial workers in the 1930s. After resigning as head of the CIO in 1941, he took the Mine Workers out of the CIO in 1942 and in 1944 took the union into the American Federation of Labor (AFL)." From Wikipedia
John L. Lewis led several strikes during the Truman administration. Depsite this, Truman wrote in a note that he was "fond" of Lewis.
Read more about him at the American Federation of Labor and Congress of Industrial Organizations or in the Times' reporting on his from 1948 to 1952.
See the charismatic Lewis speaking to an audience.

5/18/48 NYT Caption: Mine Operators open contract negotiations. I made several shots of the leaders of the conference as they conferred over nominations officials of the conference. Left to right changed several times, but in the group shot in which Lewis and O'Neil were seated and writing out the names of the [...] the left to right was: [...] seated (Left to right)----Lewis, CHarles O'Neil, representing Pa. Coal Operators Association and spokesman for the operators.
Standing (left to right)---Thomas Kennedy, vice-president of UMW (shortest man, glasses with dark suit and tie), and Harry Moses, representing U.S. Steel coal interests (captive mines), (he is wearing light suit with glasses), John Owens, Sec-Treasury of the UMW (partially bald and mustache).