Deborah Samson would be brimming with envy over Marine Lance Cpl. Ryann Campion's current tour of duty in Afghanistan.

In 1782, enraged that women were not allowed to fight the British in the Revolutionary War, Samson used the identity of her deceased brother Robert Shurtliff, cutting her hair and dressing in men's clothing to join the Continental Army. She became a heralded soldier - and the first woman to fight for her country.

Campion's enlistment required no such extraordinary efforts. A few years ago, the 19-year-old from Hatboro merely walked over to Marine recruiters near a local car show as they challenged passersby to try a pull-up bar.

"I hopped up. After I was done, I talked to them for a brief moment and I was hooked," Campion writes in an e-mail from Afghanistan, where she is a driver, cook, and member of a female military team that interacts with Afghan women.

In the nearly 230 years of service separating Samson and Campion, women have become an essential part of the U.S. military.

"Forget about wars. I don't think we could staff our military without being able to get half the population to participate, and half the population is women," says retired Army Col. Jim Martin, now a professor of social work at Bryn Mawr College.

George Wright, Army spokesman at the Pentagon, said there are unique advantages to having servicewomen in Iraq and Afghanistan. "The role of women has been very helpful to us in dealing with the local population," Wright said. "We're finding that women are more adept and successful at reaching out to the local women."

Worldwide, women make up about 14 percent of U.S. active-duty forces - the largest percentage in the country's history.

Since the beginning of Operation Iraqi Freedom in 2003 and Operation Enduring Freedom in Afghanistan in 2001, women have accounted for 11 percent - or 231,876 - of the 2,022,975 U.S. service members in those conflicts. Figures from the end of October show 26,683 women currently deployed in those operations.

Of the 5,429 total enlistments into the active-duty Army in the last three years from the Philadelphia recruiting region, including the suburbs and all but the tip of northern New Jersey, 758 - or about 14 percent - were women.

In Iraq and Afghanistan, women serve as fighter pilots and as security escorts for convoys, go on patrols and staff checkpoints - unlike in World War II, when at the peak of 400,000 female service members, the assignments were mainly as nurses and clerical workers.

More than 120 women have died during their service in Iraq and Afghanistan and more than 600 have been wounded in action. Though technically women are still barred from direct combat, unpredictable attacks, blurry front lines, and personnel demands have put them in the thick of battle.

Women also have reached higher ranks.

Gen. Ann E. Dunwoody, 56, rose to the upper echelon of Army command last year when she became the first female four-star general. Dunwoody is in charge of the Army Materiel Command, which equips, outfits, and arms all soldiers. In even greater contrast to the traditional male image of the military is Command Sgt. Maj. Teresa L. King, 48, named this year as the Army's top drill sergeant, leading all drill-sergeant training.

E-mail and Internet video-phoning keep families in closer touch - which can be as hard as it is joyous for women, who more often than their male colleagues are the chief caretakers of their children.

"Women have all the involvement in the war zone, yet they are very connected to what's happening on the home front in real time," says Paula Schnurr, deputy executive director of the Veterans Affairs National Center for PTSD.

But there is no substitute for an in-person parent, daughter, or granddaughter.

"In the beginning, it hit me so hard it actually put me in the hospital," says Campion's grandfather, Bill Campion, 67, a retired computer database administrator in Hatboro. "If she's on the road, I worry about land mines. If she's at post, I worry about bombs."

Children use simpler terms.

Harrison Guy 3d was about 7 when his mother, Lila, of Sharon Hill, left for Iraq with the Army's 101st Airborne Division. "I felt sad because I missed her," says Harrison, now 10.

Problems accompany the nearly full integration of women into the military. Adjustments include attending to women's health and hygiene needs in the field - but those are among the easier changes to make.

The nonprofit group Iraq and Afghanistan Veterans of America says one-third of women were sexually harassed while serving in Iraq and Afghanistan. There have been 163 reports of sexual assault in those military conflicts.

The military's response to pregnancy also is still evolving. Advocates for female service members are urging longer post-birth deployment deferrals for the 10 percent of military women who become pregnant each year. Critics say maternity leaves and months-long deployment deferrals hurt unit readiness.

"Pregnancy often results in getting very little out of a woman during a term of enlistment," says Kingsley Browne, a law professor at Wayne State University and author of Co-Ed Combat: The New Evidence That Women Shouldn't Fight the Nation's Wars.

Browne notes the recent case of Army Spec. Alexis Hutchinson, 21, in Savannah, Ga., pregnant during her enlistment. She refused to deploy to Afghanistan because caretaking arrangements for her 10-month-old son fell through. She is confined to her base during an investigation.

The military says it is supportive of parents and its pregnant members. That support can erode on an individual level.

"The fact that women can avoid their duties because of pregnancy can create substantial resentment among those, both male and female, who must take up the slack," Browne says.

Women's reasons for enlistment differ little from men's. Patriotism, thirst for adventure, steady work, and great benefits, including health insurance and strong child-care facilities on bases, are primary motivators, recruiters in the Philadelphia region say.

Child care is a big concern: A 2007 congressional report says 38 percent of active-duty women have children; about 11 percent of active-duty women are single parents.

The military's health-care system is still catching up to the increasing number of servicewomen suffering the same battlefield-related injuries as men. Women come home with brain trauma, lost limbs, and post-traumatic stress disorder (PTSD).

In 2008, the Rand Corp., a nonprofit think tank with headquarters in California, conducted the first large-scale, nongovernmental study of "psychological and cognitive needs" of service members who were in Iraq and Afghanistan.

Nearly 20 percent of the 1,965 respondents reported symptoms associated with PTSD or major depression. Women were more likely to report those problems, but less likely than men to report pain.

The transition back to civilian life carries different challenges for women.

"Men are more apt to be able to ease in over time into their roles as fathers and husbands," says Lory Manning, director of the Women in the Military Project at the Women's Research and Education Institute in Washington.

"Kids want their mom functioning from the minute she walks off the plane," Manning says.

Homelessness and failing marriages also are on the rise for women vets - one study shows marriages of female service members breaking down at nearly three times the rate of male troops.

Kim Campion-Roig, Ryann Campion's mother, believes that good things will flow from her daughter's enlistment in the Marines.

Still, she won't relax until Campion is home, soon for Christmas and again in April when her daughter's deployment is scheduled to end.

"It's just such a sickening feeling knowing that she's over there."

Contact staff writer Carolyn Davis at 215-854-4214 or cdavis@phillynews.com.