When Ms. was launched as a “one-shot” sample insert in New York magazine in December 1971, it was a brazen act of independence. At the time, the fledgling feminist movement was either denigrated or dismissed in the so-called mainstream media. Most magazines marketed to women were limited to advice about finding a husband, saving marriages, raising babies or using the right cosmetics. To pay tribute to five decades of reporting, rebelling and truth-telling, Ms. gives you From the Vault, ma...