The usual phrase is by popular demand, but when the request is made by a single visitor, that would be a bit much. Still, a single visitor represents such a large percentage of my readership, I thought I should respond. The search box is back in the menu bar above.
There was (and still is) a search box available for all postings before March of this year. [Right hand column, down a bit] Now the months after March are searchable, too.