Which preposition to use with tailoresses

of Occurrences 3%

In that year the tailoresses of New York formed a union.

in Occurrences 2%

We have no reason to believe that the names of Lavinia Waight and Louisa Mitchell, the leaders of New York tailoresses in 1831, were known to Sarah Bagley or Huldah Stone, when in 1845 they stirred Lowell.

Which preposition to use with  tailoresses