A friend offered me the book Do-Gooders: How Liberals Hurt Those They Claim To Help. I've enjoyed the book, especially the last chapter (on education, of course). In it, Mona Charen echoes Loewen's complaint. From pp 234-235:
This is America through the eyes of liberals. It is the horror of slavery without the uplift of the Abolitionist movement. It is the greed of the "robber barons" without the ingenuity of the Edisons and the Wright Brothers. It is the shame of the Japanese internment without the glory of Iwo Jima. America's children are fully versed on the stain of slavery in American history but not on the great benevolence and sacrifice that that evil brought forth. Youngsters know about Sojourner Truth, but not about William Lloyd Garrison, the Underground Railroad, Uncle Tom's Cabin, and Frederick Douglass...Every nation has moral stains in its history, but American children should know that their ancestors struggled to--and largely succeeded in--overcoming theirs.
When some people advocate teaching "warts and all", they often forget the "and all". Back to Loewen, p. 88: "The antidote to feel-good history is not feel-bad history but honest and inclusive history."
Update, 5/28/07: Apparently, the teaching of US history doesn't have to suck.