More than 1,500 U.S. military personnel have died in Iraq since the U.S. invasion began two years ago, but nearly four times as many have been wounded in combat too seriously to return to duty. For the first time in American history, a substantial number of the combat wounded are women -- in part because the front lines in this war can be anywhere. As part of our Span of War series marking the two-year anniversary of the war in Iraq, NPR's National Correspondent Linda Wertheimer visited with some of the women who are recovering from severe wounds at the Brooke Army Medical Center in San Antonio, Texas. By the Numbers: Women in the Military Women have served unofficially as support personnel, spies and soldiers throughout American history. Women gained an official role in the U.S. military with the formation of the Army Nurse Corps in 1901 and Navy Nurse Corps in 1908. The first women to enlist in the U.S. military joined the Navy and Marines during World War I. Currently: · 350,000 women are serving in the U.S. military -- almost 15 percent of active duty personnel. · One in every seven troops in Iraq is a woman. · 35 women soldiers have died as of March 2005. · 261 U.S. military women have been wounded in Iraq. Spanish American War: · 1,500 women served. World War I: · 21,480 in the Army Nurse Corps · 2,000 in the Navy Nurse Corps · 12,000 Yeomen · 305 Women Marines · 200 in Army Signal Corps · More than 400 nurses died in the line of duty. World War II Era: · 400,000 women served. · More than 460 died. · 88 female military nurses were captured and held as prisoners of war. Korean War era: · More than 50,000 served. Vietnam: · 265,000 women served. · 7,500 women were deployed in theater, including 36 women Marines, 421 women in the Navy and 771 in the Air Force. The remainder served in the Army. · Navy, Air Force and Army nurses accounted for 80 percent to 90 percent of the total number of women who served in Vietnam. · Majority of U.S. women serving were in their early 20s. When they returned to the United States, they received the same hostile treatment as did men returning from combat duty. · 48 percent of women Vietnam veterans are expected to experience post-traumatic stress disorder at some point. · Many women have also encountered health problems from Agent Orange exposure and experienced suicidal thoughts. Operation Desert Storm: · In January 1991, more than 33,000 servicewomen deployed to Southwest Asia during Operations Desert Shield and Desert Storm. · 13 servicewomen were killed and two were held as POWs. Sources: Department of Defense; the Women For Military Service in America Memorial in the Arlington Cemetery. Connie Spinks, pictured with her mother, Annette, was wounded the day after her 22nd birthday. A car bomber collided with the Humvee in which Connie was riding in northern Iraq. Annette says her husband deeply regrets letting Connie join the Reserve. Connie Rendon, shown with her husband Hector, was 40 when she was wounded in an ambush on her truck north of Baghdad. Shrapnel broke her jaw and is still embedded in her face. Her hands were burnt and broken, her ribs smashed; one lung collapsed.