Your John Hull, Amelia, and Robert Triggs were St. Croix County (WI) people. That board may be of some help you.
I picked up that fact by checking just now in a couple of my subscription databases. They also show that Charles Hull (John & Amelia's son) was born in Minnesota. So, that puts John & Amelia there in the late 1850s. John Hull was born in NY (1831), same as Amelia (though different years).
The following are the resources for the above information:
Civil War Pension Records:
Robert Triggs, Jr., was a resident of Kinnickinnick, St. Croix Co., WI when he enlisted in Co. A, 12th Wisc. infantry (10-30-1861). After he was killed in action in Atlanta (7-21-1864), Amelia Triggs filed for his pension (on 10-13-1864). She apparently died in 1891, since Robert's pension was transferred to dependent Stephen W. Triggs on June 21 of that year.
Robert Triggs was included posthumously in the 1890 census -- as deceased veteran -- by the census taker in Pleasant Valle, St. Croix Co., WI. So I assume that was where his family (ie., Amelia and any others in the house) were living at that time. If that's a year before she died, which is my guess, she probably died in that area.
1860 Federal Census -- Malone, St. Croix Co., WI:
HULL, John, 29, farmer, born NY.
HULL, Amelia, 23, wife, born NY
HULL, Charles, 1, born MN.
WEBSTER, Albinus, 26, farmer, born NY (living w/ J. Hull & family)
Let me know if these things do you some good, Sallie. I'll be interested to know!