...The Great American Photo Scanning Month. Go to ScanMyPhotos.com to see how you can get 1,000 4" x 6" photos scanned and put on DVD for only $19.95 return shipping. Also, see my notes on Scanfest and Spring Break Scan-a-thon at the bottom of this post.
...National Volunteer Month. See my post on being a volunteer back during Random Acts of Kindness Week.
...National Jewish-American Heritage Month.
April 6 - National Tartan Day (USA)
Sunset of April 19th - April 27th: Passover
April 27 - May 4: Yom Hashoah (Holocaust Remembrance Week)
Does the above feature in or affect your heritage, culture, or family history?
April 1: 45th Edition of the Carnival of Genealogy - Cars As Stars
April 9: 3rd Edition of the "Where Were You?" Carnival - the Civil War (and also here)
April 15: 46th Edition of the Carnival of Genealogy - "What Traits Run in Your Family?"
April 21: Cabinet of Curiosities #6
April 27: 5th Edition of the Carnival of the Carnival of Irish Heritage & Culture - Irish Gaelic Names and Words
April 27: 6th Edition of the Carnival of Central and Eastern European Genealogy - a Carousel edition (choose your own topic)
April 1 - 6 (continued from March 29th): Spring Break Scan-a-thon
Part of Scan-a-thon includes extra Scanfests: Tuesday, April 1 and Thursday April 3 from 3:00 - 6:00 PM, PDT
April 27th: Scanfest, 11:00 AM - 2:00 PM, Pacific Daylight Time