Actually about 40% of military officers from Virginia stayed loyal to the union and did not join a rebellion to establish a country based on slavery. Here is a list of other prominent southerners who stayed loyal to the Union. They should be lauded for making the right choice. Lee chose poorly.
John Minor Botts[9]
Thomas E. Bramlette[10]
Robert Jefferson Breckinridge[11]
William Gannaway Brownlow[12]
William Cannon[13]
William Crutchfield[14]
Thomas H. DuVal
Emerson Etheridge[15]
Andrew Jackson Hamilton[16]
Joshua Hill[17]
William Woods Holden[18]
Joseph Holt[19][20]
Sam Houston[21][22]
Fielding Hurst [23]
Andrew Johnson [24]
Newton Knight
David Farragut
William Hugh Smith
Francis Lieber[25]
Montgomery C. Meigs[26]
Isaac Murphy[27][28]
Thomas Amos Rogers Nelson[29]
James L. Petigru[30]
Francis Harrison Pierpont[31]
Joseph G. Sanders[26]
Winfield Scott[26]
James Speed and Joshua Fry Speed[32]
George Henry Thomas
Elizabeth Van Lew
James Madison Wells[26]
God! Here is the propaganda again. The UNITED STATES was a country based on slavery.
When the Declaration of Independence was signed, all the states were slave states. By 1889, when the US Constitution was ratified, the vast majority of the states were still slave states.
Slavery was legal in the Northern states all through the War, and it lasted six months longer in the Union states than it did in the Confederacy.
Lincoln urged passage of the "Corwin Amendment" that would have made it permanent.
No effort to pass a constitutional amendment to abolish slavery was ever put forth, and had one been put forth, it would have failed to pass.
The US Constitution explicitly protects slavery in Article IV, Section II.
The Civil War was two slave nations fighting over money. It wasn't any noble cause, it was down right dirty greed and power behind that war.