I am sorry to say you are a bit misinformed(Unless I am)-E. Canada is Ontario not Quebec. Lower Canada is Quebec & Upper Canada is Southwestern Ontario.
Mosses was in E.Canada from birth in 1820 to possibly 1849.
Mathilda was b. in Detroit ,Mich. All her children were b. in Wis.. Isaac Marr. in Wis. if memory serves me correct.
Have checked all Wis. Vitals, LDS records,Tanquay,Jette& Loiselle to no avale. Cannot connect any other St Antoines with us as have no idea where in E. Canada was born & no idea who parents or additional siblings were. Many of their dates were to early or to late, & from other states etc.. Running blind here. Any other help would be much appreciated. Thank you so much. Kathy Fuhrman