Army Wives was cancelled in 2013; however, the entire series can be found on the popular streaming sites Hulu and Netflix. The Lifetime website also has free videos and clips from the show, but it doesn't offer full episodes as of June, 2015.
Army Wives ran for seven seasons from 2007 through 2013, making it the longest-running Lifetime series in history. After it was canceled, the network ran a two hour special on March 16, 2014 with interviews with real-life army wives and discussions with the cast about great moments from the show. Unfortunately, the two hour special is not available online.