Here, have some some highlights from the US Bureau of Labor Statistics!
On labor force participation:
In 2013, 57.2 percent of women were in the labor force, down 0.5 percentage point from 2012. Men’s labor force participation, which always has been much higher than that for women, also was down in 2013, from 70.2 percent to 69.7 percent.
Labor force participation varies by marital status and differs between women and men. Among women, divorced women had the highest labor force participation rate, at 64.7 percent. The rate for married women was 58.9 percent. For men, those who were married had the highest labor force participation, 74.2 percent. Divorced men had a labor force participation rate of 66.8 percent.
On occupation and industry:
In 2013, women accounted for 51 percent of all workers employed in management, professional, and related occupations, somewhat more than their share of total employment (47 percent). The share of women in specific occupations within this large category varied. For example, 20 percent of software developers and 33 percent of lawyers were women, whereas 62 percent of accountants and auditors and 81 percent of elementary and middle school teachers were women.
Employed Asian (48 percent) and White (43 percent) women were more likely to work in higher paying management, professional, and related occupations in 2013 than were employed Black (34 percent) and Hispanic (26 percent) women. Meanwhile, Hispanic (33 percent) and Black (28 percent) women were more likely than Asian (21 percent) and White (20 percent) women to work in lower paying service occupations.
In 2013, women accounted for more than half of all workers within several industry sectors: financial activities (53 percent), education and health services (75 percent), leisure and hospitality (51 percent), and other services (52 percent). However, women were substantially underrepresented (relative to their share of total employment) in agriculture (24 percent), mining (13 percent), construction (12 percent), manufacturing (9 percent), and transportation and utilities (24 percent).
In 2013, women who worked full time in wage and salary jobs had median usual weekly earnings of $706, which represented 82 percent of men’s median weekly earnings ($860). Among women, earnings were higher for Asians ($819) and Whites ($722) than for Blacks ($606) and Hispanics ($541). Women’s-to-men’s earnings ratios were higher for Blacks and Hispanics (91 percent for each group) than for Whites (82 percent) and Asians (77 percent). (See table 16; note that the comparisons of earnings in this report are on a broad level and do not control for many factors that may be important in explaining earnings differences.)
Emphasis is mine. There is a pay gap. The question is, what is responsible for that pay gap? Differences in educational attainment, occupational trends, hours worked, and years of experience all affect this overall average, which is lower for women than men. The cultural idea that women should be homemakers, bearing and raising children, all of which is unpaid labor, is responsible for some of that gap. Women, on average, work fewer hours than men, and the hourly averages work out to $19.60 for women, versus $21.18 for men, which is 92.5% of what men are paid [Edit: upon careful rereading, that might not be accurate; it looks like the BLS may have taken some of that into account, as average weekly earnings are for people who work full-time, and the 36hr vs. 40.6hr average work week difference is due to more women working part time?].
There is a whole wikipedia page examining the US gender pay gap with a ton of theories and sources. It's not as simple as "all men and women are paid the same!" or "every woman earns eighty-two cents of a man's dollar!"