All the Massachusetts Grand Army
buttons of 1775 have a dot border.
When these regiments were absorbed into the Continental Regiment of 1776 they continued
to use the 1775 buttons in addition to the borderless style of numbered button.
Top Row (L-R): Read's 6th Reg't (later the 13th Continental), Mansfield's 7th Reg't (later the 27th Continental), Frye's 10th Reg't
Bottom Row (L-R): Nixon's 16th Reg't (later the 4th Continental), Doolittle's 18th Reg't