The letter ‘J’ was the last letter added to the English alphabet, which dates back to 1524.

The letter 'J'

Prior to the introduction of letter ‘J,’ the letter ‘i’ served for both the ‘i’ and ‘j’ sounds in the English language. The distinction between these sounds led to the creation and inclusion of the letter ‘J’ to better represent the evolving linguistic nuances, marking a notable historical development in the English alphabet.