I haven't found the marriage of Jacob and Martha, but it should be in Berkshire County, MA.
This appears to be your Jacob:
Jacob Jackley (junior) in the 1860 census in Lanesborough, Berkshire, Massachusetts, is the second oldest child of parents Jacob (senior) and Mary. His siblings in this census are John, Agnes, Christine, Thomas, Mary M, and Lilly.
First child of Jacob Jackley Jr. and Martha Dano was Jessie, born 1867 in Lanesborough, Berkshire, Massachusetts.
Therefore it makes sense that Jacob and Martha married in Berkshire County, Massachusetts, probably before 1867.
Martha Dano was Jacob’s second wife, per findings in another Genforum thread re. this family (seems there are many family historians!). I did not note the death of the first wife - but Martha and Jacob most likely married after she died.
Alternate name spellings (helpful for those searching digital archives):