UnScramble this Word: a c e s o e h l?

Questions

History - On what was Pennsylvania incorrectly spelled?

History - The Empire State Building was completed in 1930, 1931 or 1932?

History - The date of which Christian festival was fixed in 325AD by the Council of Nicaea?

History - The first charity flag day was held in 1914, 1917 or 1919?

History - The first metered taxi become operational in 1899, 1903 or 1907?