In 1823 the Arsenal building became the house of refuge of the Society for the Reformation of Juvenile Delinquents, the first organization instituted in America to care for youthful offenders.

In 1839 it was destroyed by fire.

That was two years after the Parade Ground had been reduced to its present limits of 6.84 acres and renamed in honour of President Madison.

In 1844 the Eastern Post-road was closed.

Its course may still be traced by the double row of trees that runs northeast towards Madison Square Garden.
In 1847 the Square was formally opened and soon after society began to migrate there.