Blewcoat School was founded in 1688. A statement of about 1700 suggests that this was done in response to the establishment of free Catholic schools in the area, with local Church of England members contributing to a public subscription.
The school moved to Caxton Street, Victoria, in 1709; brewer William Green paid for the building. It was originally a boys' school, and only began admitting girls five years after this move, which presumably explains the single figure.
The school closed in 1928, and after varied uses was acquired by the National Trust in 1954. Today, they run it as a cafe and shop. However, the fabric of the building carries a reminder of World War II, when it was a store guarded by American troops. Presumably rather bored with their job, they carved graffiti in the brickwork: the words 'US Army' remain clearly visible. (I can't claim the credit for spotting this - it was pointed out on a very interesting Blitzwalkers guided walk.)