What event made Calvin Coolidge a national figure?

Calvin Coolidge became a national figure during the Boston Police Strike of 1919. As the Governor of Massachusetts at the time, he took a strong stance against the striking police officers, asserting that "there is no right to strike against the public safety by anybody, anywhere, any time." His decisive action to call in the National Guard to restore order garnered national attention and praise, positioning him as a champion of Law and Order. This event ultimately boosted his political profile, leading to his nomination as Vice President in 1920 and later his presidency.