The man who would become known as the greatest chronicler of America's sexual experiences was born in the gritty, waterfront tenement town of Hoboken, New Jersey, on June 23, 1894. Alfred Charles Kinsey was the first of three children born to Alfred Seguine Kinsey, an instructor of shop practice at Hoboken's Stevens Institute of Technology, and his wife Sarah Charles Kinsey. Alfred Seguine was a domestic autocrat, an ardent prohibitionist, and a devout Methodist who took his family to church at every possible opportunity: three times on Sundays, plus assorted midweek services and social gatherings. Sarah Charles, in the words of Kinsey's biographer James H. Jones, was "shy and soft-spoken, possessed of a personality at once retiring and diffident." If this does not seem like a formula for domestic tranquility, indeed it was not, for Kinsey's parents' marriage would end in divorce in 1931.

Sex Shy
Yet this was the household in which one of America's most influential sexual revolutionaries grew up, a man who championed sexual freedom for men and women alike, whether heterosexual or homosexual; who believed both that sex was good and that a good sex life was the surest guarantor of a happy marriage. The roots of Kinsey's interest in sex, which was to propel him to controversial stardom in the 1940s and 1950s, are to be found here. By all accounts, the Kinsey household was asexual, with parents displaying little affection for each other. Kinsey had little interaction with girls outside the schoolroom. His adolescent explorations of sexuality left him deeply troubled, obsessed with masochism and unsure of his own sexual orientation. When Kinsey met his future wife in 1920, still grappling with his repressed childhood, he had never once been on a date with a woman or had sexual intercourse.

Nature and Camping
Alfred was a delicate and unhealthy child with neither interest in nor aptitude for sports, but he did excel in the classroom. An influential high school biology teacher stirred his interest in nature and science. Young Kinsey took to spending his afternoons and weekends rambling through the hills and marshes that surrounded South Orange, New Jersey, where his family had moved in 1904. In 1908 he started summering at the YMCA camp at Lake Wawayanda in rural northwestern New Jersey, where he studied nature and learned wilderness survival skills in the company of boys his own age. Kinsey's attachment to camping was so deep that he was to continue as a camper, and later a counselor, into the early years of his marriage. In 1911 he joined the Boy Scouts, becoming an Eagle Scout in 1913.

A "Second Darwin"
In 1912 Kinsey graduated from high school as valedictorian of his class. His interest in biology was well known to his classmates, whose official "class prophecy" dubbed him the "second Darwin," but at his father's behest he applied to only one college, the Stevens Institute of Technology. Despite what appears to have been a deliberate attempt to fail the entrance examination, Kinsey entered Stevens that fall, but he neither liked Stevens nor did particularly well there. In June of 1914 he withdrew and, severing all ties with his father, transferred to Bowdoin College in Brunswick, Maine, which had a fine reputation in biology. Kinsey flourished at Bowdoin and graduated in June 1916, winning a prestigious competition to give the college's commencement address. None of his family attended his graduation.

A Specialty in Bugs
That fall Kinsey arrived in Boston at the Bussey Institute, Harvard's graduate school of applied biology, to begin work on his Doctor of Science (S.D.). The dean of the school, Monroe Wheeler, was an entomologist and taxonomist, and he cultivated Kinsey's childhood interest in insects with great success. Kinsey eventually decided to write his dissertation on the gall wasp, a tiny insect that made its home in oak trees, on whose branches its burrowing produced the tumescent growths known as galls.

Collector's Approach
Foreshadowing the ardent diligence that was to characterize his sex research, Kinsey insisted on collecting many thousands of gall wasp specimens for his doctoral project, when the norm for taxonomic studies at the time was but a few dozen. During graduate school, Kinsey also came to believe that science held the key -- truth -- by which humanity could uplift itself, a doctrine that both inspired and dominated his work on human sexuality. Kinsey received his Doctor of Science in 1919, and after a yearlong traveling fellowship (which he used to collect even more gall wasps), he arrived in Bloomington, Indiana, in August 1920 as a very new assistant professor of entomology at Indiana University at the salary of $2,000 -- about $21,000 in 2004 dollars.

The Naturalist
When Alfred Kinsey first arrived in Bloomington, he taught Indiana University students introductory biology, advanced entomology, and insect taxonomy. As a teacher, he greatly preferred the field to the classroom, taking his students on frequent trips so that they could see nature at work. In 1926, he authored a high school textbook, An Introduction to Biology, that eschewed theoretical lectures for experimentation and firsthand experience. In it, Kinsey came out strongly in favor of Darwin's theory of natural selection -- notably so, given that a Dayton, Tennessee, jury had convicted John Scopes of illegally teaching the theory of evolution only a year before. Like his father, Kinsey had little patience for imperfection, expecting the same diligence and standards of his students to which he drove himself. One of his graduate students recounted a final examination in which Kinsey gave him a few seconds to glimpse the contents of a box of gall wasps, and then demanded that he say how many species the box contained.

Changing the World Through Science
At heart Kinsey saw himself not as a teacher, but as a scientist of the first rank and a missionary whose destiny was to change the world through science. He wanted his work to go beyond cataloging and enumerating one species of insect after another, to plumb for answers to the great questions of evolution, natural selection, and the origin of species.

Intense Collecting
In pursuit of big answers, he turned his scholarly eye once more to the gall wasp, the subject of his doctoral dissertation. In a series of lengthy field trips around the country between 1926 and 1929, and in Mexico in 1931 and 1932, Kinsey and his protégés collected some 17,000 gall wasps and 54,000 galls. On these expeditions he drove his students as hard as he drove himself, insisting that they gather specimens from sunrise until sunset, then by the light of the campfire sort the day's haul into individual cloth bags. Back in Bloomington, the students were tasked with mounting each wasp on its own pin and affixing beneath it its own personal label.

No Two Alike
Finally, in 1930, Kinsey published the fruit of his labors, a monograph entitled The Gall Wasp Genus Cynips: A Study in the Origin of Species. Though well received by fellow entomologists, the volume was somewhat less effective as an attention-getter, for gall wasps were -- and remain today -- an extremely narrow specialization within the already specialized world of entomology. Nonetheless, one has to admire Kinsey's achievement as well as his dedication: Of the 93 species that he described in the book, 48 had never been identified before. Beyond that, Kinsey discovered that no two individual wasps were alike, and in this he found ready proof of the tenet of natural variation, that no two individuals -- be they insects or people -- are made alike. In 1935 Kinsey published his second major work on gall wasps, The Origin of Higher Categories in Cynips, but by then his interest in human sexuality was pulling him in another direction. He would never publish another monograph about gall wasps.

Last Years
Alfred Kinsey's last years were marked by controversy. The Cold War brought with it political crusades and a large measure of fear that American society was being corrupted. In 1953, following the publication of Kinsey's report on female sexuality, a committee of the U.S. House of Representatives chaired by Tennessee congressman B. Carroll Reece started investigating Kinsey and the Rockefeller Foundation for possible ties to the Communist Party. Over medical director Alan Gregg's objections, Dean Rusk, the foundation's newly appointed president (and, later, secretary of state in the Kennedy and Johnson administrations), terminated Kinsey's funding.

Kinsey was devastated, and though he spent the next two and one-half years trying to secure funding from alternate sources, he never succeeded. At the same time, his health was declining, as years of stress, long hours, sleeplessness, and ever-advancing congestive heart failure took their toll. In August of 1956, he fell while working in his garden, bruising his leg and causing a fatal embolism; several days later, on August 25, he died.

The Beginnings of Change
Kinsey died disappointed that he hadn't persuaded the world that sex was good, and that tolerance of the enormous variety of sexual behavior that existed was right. But his dream did not die with him. Kinsey lived just long enough to see the American Law Institute's Model Penal Code, published in 1955, embrace the right of consenting adults to engage in homosexual and anal sex. As the code was adopted by state after state, the old crime of sodomy ceased to exist. In 2003, the U.S. Supreme Court dealt the final blow to the country's few remaining sodomy laws, overturning Texas's prohibition of homosexual sex in its landmark ruling in Lawrence v. Texas.

Masters and Johnson
Following hot on Kinsey's heels, William Masters and Virginia Johnson began their own epic studies of sexual behavior, using a specially designed polygraph-like device to record the sexual response of more than 700 subjects observed during masturbation and intercourse. Masters and Johnson's work coincided with the sexual revolution of the late 1960s and early 1970s, in which hippies expounded on the benefits of free love and implored people to "make love, not war." Masters and Johnson built on Kinsey's biological approach, but went beyond "what people do" to try to discover "how it works" and how to overcome particular sexual problems such as frigidity, impotence, and premature ejaculation. Eventually they founded a clinic in St. Louis to treat sexual dysfunction, paving the way for the commercialization of treatments for sexual problems like erectile dysfunction that began in earnest with Pfizer's introduction of Viagra in 1998.

Increased Reproductive Rights
At the same time, the country was fighting a battle about whether sex was solely about procreation, as Victorian morality had once taught, or whether the free exchange of pleasure between partners was reason enough to have sex. In 1960, the Food and Drug Administration approved the nation's first oral contraceptive. Within a few years, millions of women were taking the drug, and freeing themselves to engage in sexual intercourse on their own terms without the risk of becoming pregnant. The Supreme Court's 1973 decision legalizing abortion in Roe v. Wade extended women's reproductive rights to the safe termination of accidental pregnancies.

Ongoing Conflict
Kinsey would have approved: The country's legal and medical apparatus had finally converged to make the pursuit of sexual pleasure for its own sake safe and legal. But the three decades since Masters and Johnson and Roe have yielded mixed results for the proponents of sexual liberalism. Roe elicited strong opposition from the very start, and people opposed to abortion have mounted a sustained and sometimes successful series of campaigns, in and out of court, to reduce women's access to the procedure. With the dawn of the era of AIDS during the 1980s, the question of sex became one of public health. But while public health concerns demanded that the government pursue the study of sex in order to understand why people engage in risky sexual behavior, those in favor of sexual conservatism have sought to end public funding for the research. Yet sex research has endured -- and of that, Kinsey truly would have been proud.