Krock entered Princeton in 1904, but dropped out in the middle of his freshman year for financial reasons. He nonetheless maintained a lifelong connection to the university, which awarded him an Master of Arts in 1937, and to which he left his papers. He completed his formal education at Lewis Institute, Chicago, earning an Associate's degree in 1906.
Krock's career began as a general assignment reporter in 1907 for the Louisville Herald. Within a year, the paper faced financial troubles.
After a brief stint as a deputy sheriff in Jefferson County, Kentucky, he resumed his newspaper career with the Associated Press in Louisville. By 1910 he was in Washington as a correspondent for the Louisville Times and, after 1911, for the Louisville Courier-Journal as well.
In 1915 he returned to Louisville to become executive manager of both the Times and the Courier-Journal. In 1919 he was named editor-in-chief of the Louisville Times, and in that position attended the Versailles Peace Conference. In 1923, following a dispute with Robert W. Bingham, the newspaper's owner, over editorial policies, he resigned in protest at the publisher's support of Prohibition and woman suffrage. He immediately joined Ralph Pulitzer's New York World as an assistant to the president and then as an editorial writer. He left the World for the New York Times in 1927, becoming a member of its editorial board. In 1932, he went to Washington as the Times's Washington correspondent and bureau chief. In the next thirty-five years, he would dominate the New York Times's coverage of the federal government. From 1932 to 1952 he wrote every lead story on the biennial elections, and although he supplied four opinion columns per week (and one on Sunday), he generally wrote the principal daily story out of Washington as well.
As an editor, he shaped the Washington bureau into a powerful fiefdom that continually warred (usually successfully) with the home office in New York. A conservative among liberals, he avoided confrontations, according to James Reston, who succeeded him as bureau chief in 1953, but he commanded respect and often put his job on the line when his authority was challenged or the freedom of his reporters was threatened. As bureau chief, he was stern and demanding, but he abhorred meetings--he held only three staff conferences during his twenty-one years as the man in charge--and took the position that his reporters knew what they were doing, until proved otherwise. He always addressed them formally, never by their first names, and expected similar address from them. As Times lore has it, he was once asked by a newly hired reporter how long someone had to be in the bureau before he could be called by his first name, and Krock replied, "For as long as you care to remain here. "
Coming to Washington as the New Deal was changing the role of government, he recognized that political reporting would also change. He deliberately hired specialists, looking for reporters with strong preparation in political science, history, and especially economics, the areas on which his own reading centered and which he believed were essential to understanding what was happening not only in Washington but everywhere in the world. Fifteen months after he assumed control of the Washington bureau, Krock was asked to develop a signed column to appear on the editorial page, an innovation that represented a radical departure from the established practice of using only unsigned editorials to express the paper's opinion on current events. "In the Nation, " as his column was titled, offered background information, critical analysis, and personal commentary until his retirement in 1966; along with similar columns by David Lawrence and Walter Lippmann, it provided the model for papers everywhere. Krock's voice became increasingly conservative as the years passed. Although he saw himself as a liberal democrat within the tradition of Jefferson and Wilson, he believed that the New Deal represented a sharp, even radical, and ultimately misguided break with the party's past. He was particularly apprehensive about the growth of presidential power. "I am, " he once said, "a walking allergy to Presidents that soon becomes insufferable. "
After his retirement from the Times, Krock produced several books, one of which, Memoirs; 60 Years on the Firing Line, became a best-seller in 1968.
Krock believed that the age of modern journalism was the "age of the specialist" and made it a lifelong habit to read long after midnight on a regular basis to keep himself informed or to prepare himself for some new area of inquiry or analysis.
Krock married Marguerite Polleys on April 22, 1911; they had one son. One year after Marguerite Krock's death in 1938, Krock married Martha Granger Blair, a reporter for the Washington Times-Herald.