Historical clue formulations

• One saying "We can do it!" — 2016-01-09
• Per a 1942 song, "She's making history, working for victory" — 2015-01-10
• Norman Rockwell painting subject of W.W. II — 2009-04-27
• Norman Rockwell painted her eating a sandwich — 2006-08-25
• W.W. II icon on a 1999 stamp — 2006-02-11
• Morale builder of W.W. II — 2000-11-17