The Battle of Gettysburg at 150

Seven score and ten years ago today, the Battle of Gettsyburg - perhaps the most pivotal moment in the American Civil War - was being fought in Pennsylvania. You can see how Harper's Weekly reported things at the time here, and the New York Times Disunion blog has a great assessment of "What Gettysburg Proved", here. Those two links are the tiny tip of a very large iceberg of online commentary and resources. So below, a selection of links that have caught our eye on Twitter. Please feel free to share your own suggestions for further reading in the comments.

Here's a useful hour-by-hour time of the Gettysburg battle. http://t.co/X0m6N3jhTl First shots fired 730 AM July 1.
— davidfrum (@davidfrum) July 1, 2013

Get lost in the incredible history of the Battle of Gettysburg in this interactive map http://t.co/KKbvgza4Qb
— Smithsonian Magazine (@SmithsonianMag) July 1, 2013

#Gettysburg Voices at 150: author Charles W. Mitchell shares witness accounts of the battle. #gburg150 http://t.co/ZuEIYhOjh7
— JHU Press (@JHUPress) July 2, 2013

The terror of being black in front of an advancing Confederate army #cw150 #gettysburg http://t.co/EElGLmZEr3
— HNN (@myHNN) July 2, 2013

A collection of images from the Gettysburg battlefield, 150 years later: http://t.co/EupGTn0KqO #cw150 #Gettysburg150
— US National Archives (@USNatArchives) July 2, 2013

Artists, photographers, printmakers told the tale at Gettysburg http://t.co/8w4DssvGEW
— Library of Congress (@librarycongress) July 1, 2013

Did Black men fight at Gettysburg? I discuss this question this week on @TheRoot247. http://t.co/9Bmcfmp9ah
— Henry Louis Gates Jr (@HenryLouisGates) July 1, 2013

Gettysburg's only civilian casualty was a 20 yr. old girl baking bread, waiting for her love to return from battle: http://t.co/qJdp4u6GAk
— Lapham's Quarterly (@LaphamsQuart) July 1, 2013

The Gettysburg illusion: How a re-creation of the battle helped erase the meaning of the Civil War http://t.co/T9Hb3RPEji
— The Atlantic (@TheAtlantic) July 2, 2013

The mouseover images in this #Gettysburg project by @PittsburghPG are so neat http://t.co/l0BrSdCY4d
— Adam Nekola (@nekolaweb) July 2, 2013

A must read about the #Gettysburg150 by John Hennessy. Manages to say what is on my mind, but more eloquently. #cw150 http://t.co/LqEf3Umtep
— Kevin Levin (@KevinLevin) July 2, 2013

.@mccauslj says there's still much to learn from the battle of Gettysburg. http://t.co/MZP07v4Up0
— GuardianUS (@GuardianUS) July 2, 2013

The Gettysburg Finesse: http://t.co/gmwRg3IrF7
— Timothy McSweeney (@mcsweeneys) July 2, 2013