- Mar 3 1st US wartime military conscription bill enacted
National Academy of Sciences
Mar 3 Abraham Lincoln approves charter for National Academy of Sciences
- Mar 3 Congress authorizes a US mint at Carson City, Nevada; coins identified with mint mark 'CC'
- Mar 3 Federal ironclad ships bombard Fort McAllister, Georgia
- Mar 3 Free city delivery replaces zone postage; 449 letter carriers hired
- Mar 3 Gold certificates (currency) authorized by US Congress
- Mar 3 Idaho Territory incorporated from parts of area split from Dakota, Nebraska, and Washington territories; now consists of states of Idaho. Montana, and most of Wyoming
Union Pacific Railroad Track
Mar 3 US Congress authorizes track width of 4'8½" for Union Pacific Railroad
- Mar 4 Battle of Thompson's Station, Tennessee
- Mar 4 Territory of Idaho established
- Mar 11 25th Grand National: George Stevens wins his 2nd GN aboard 4/1 Emblem; winning mare's full sister Emblematic wins the following year
- Mar 17 Battle of Kelly's Ford, Virginia with 211 causalities
- Mar 19 Confederate cruiser SS Georgiana destroyed on her maiden voyage with a cargo of munitions, and medicines then valued over $1,000,000. Wreck discovered exactly 102 years later by teenage diver and pioneer underwater archaeologist E. Lee Spence.
- Mar 21 Naval Engagement at Havana, Cuba: USS Henrick Hudson vs Confederate blockade runner Wild Pigeon
1st Army Medals of Honor
Mar 25 1st US Army Medal of Honor awarded to six army soldiers by US Secretary of War Edwin Stanton in Washington
- Mar 25 Skirmish at Brentwood, Tennessee
- Mar 26 Voters in West Virginia approve gradual emancipation of slaves
Day of Fasting and Prayer
Mar 27 American Confederate President Jefferson Davis calls for a day of fasting & prayer
Authors
Civil Rights Activists
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Revolutionaries
Scientists