In the three months between March 1 and June 1, 1860 - 136 slaves were manumitted by their owners in Frederick County. This was in advance of a new state law which took effect on June 1st, 1860, which prohibited the freeing of slaves.
[from John W. Ashbury's "History Moments"]
Frederick County Manumissions - 1748-1867
website by Dorinda Davis Shepley