Even more women, estimated at 25%, have been attacked by a partner or husband, the Centers for Disease Control said.
The findings form part of the first set of results from a nationwide study surveying sexual violence by intimate partners against men and women.
More than 24 people a minute reported rape, violence, or stalking, it says, with 12 million offences reported.
Experts at the Centers for Disease Control and Prevention (CDC) described the results of the first year of the National Intimate Partner and Sexual Violence Survey as "astounding".
Among the key figures included in the survey's findings were:
- more than one million women were raped in the 12 months prior to the survey, estimates show
- more than six million women and men were a victim of stalking
- more than 12 million women and men reported rape, physical violence or stalking by an intimate partner over the course of a year.
"People who experience sexual violence, stalking or intimate partner violence often deal with the effects for their entire life," said Dr Linda Degutis, director of CDC's National Center for Injury Prevention and Control.
Many of those attacked experience rape or sexual assault in their early years, with almost 80% of rape victims suffering their ordeal before the age of 25.
Some 35% of women raped before they were aged 18 were also raped as adults, Dr Degutis added.
Among the effects measured by the study, Dr Degutis said, were increased fears for safety and incidents of post-traumatic stress among victims.
Clinical conditions including asthma, irritable bowel syndrome, diabetes, frequent headaches, chronic pain and difficulty sleeping were also more likely in women who are raped or subject to assault.
There were also clear findings about the incidences of attacks on men and observations about health impacts on men who suffer rape or sexual assault.
An estimated one in 71 men has been raped at some point in their lives, the study finds.
Almost 53% of male victims experienced some form of intimate partner violence for the first time before the age of 25. Some 25% of male rape victims were first raped when they were 10 years old or younger, the findings show.
The study data was based on a survey of 9,086 women and 7,421 men from around the US, the CDC said. Results were weighted in an effort to ensure nationally representative results.
Researchers conceded that sample size limited the study, but said they felt the methods used in the survey were likely to encourage genuine responses.
Research was carried out in a health context, the CDC said, without involvement of law enforcement, in an effort to ensure respondents felt able to describe incidents that could have involved close friends or family members.
source: BBC News
You can read the full report (or just the summaries) here. Lots of really sad stats. :(