Presidential Convention
May 1 Whig convention nominates Henry Clay as presidential candidate
Henry Clay
- May 6 Johan Thorbecke argues general right to vote
- May 23 Declaration of Bab (Baha'i festival) ('Azamat 7, 1)
Historic Communication
May 24 Samuel Morse taps out "What hath God wrought" in the world's first telegraph message
Samuel Morse
- May 25 1st telegraphed news dispatch is published in Baltimore Patriot