I found a 1850 US Federal Census for a James H. Hubbard from Wisconsin
Age of James H. shows 32 years old ( b. abt 1818) and that he was born in NY,(no wife and nothing stating that James H was a widower.
Listed with him on the census: Julia A. age 5 (b. abt 1845 in Illinois), Julius M. age 19
( b. abt 1831in NY); Jane C. age 17( b. abt 1833 in NY) and a
Charles E. age 10( b. abt 1840 in Illinois) Also on the census it shows that James H was a lumber merchant and his son Julius is listed as a farmer. On this census it shows a Sarah Baxter age 21(b. about 1829 born in Wales), and a Mary J. Wheelock age 17 (b. abt 1833 born in Vermont)
Julia A. was living in Illinois at the age of 15 with A Hagar who was a Physician age 45 and he was (b. abt 1815 in Canada ) and T. H.. . who was possibly his wife age 38 (b. abt 1822 in NY.) all of this information I researched on the 1860 US Federal Census
While researching Harriet M. Hopkins on 1850 US Federal Census it shows that her parents were William C. Hopkins b abt 1807 in Rhode Island and Ruth M. Harper born about 1811 in NY.
her siblings are as follows: Josephine age 12, Oliver H. age 10, William A. age 8, Mary E. age 6 ; Iryfena age 3 and Alexander H age 0 for he was born shortly before census was taken. Then while researching more I found her brother Oliver listed as follows: Illinois Deaths: Oliver Harper Hopkins birth 29 Nov. 1840 NY Death date 5 Oct 1918 Decatur, Decatur, Macon, Ill his occupation was that of a Butcher. On the 1900 US Federal Census it shows that Oliver was widowed. There are also census records on Josephine
Mother born in Conn / father's ancestors from Wales
Moved while young to Sangamon Co Ill then went to Calif during gold strike
Married in Kendall Co., Ill to Harriet M. Hopkins on June 5, 1859
After marriage moved to Exira, Audubon Co Iowa
Harriet M. Hopkins b. 30 July 1836 in NY
Willam Clark b in Iowa, Hattie M. d young buried in Oakfield Iowa, Julia Mae (married Franklin Strain), Charles Eugene, James Edgar, George Harper a gambler, shot to death in Color and buried in Colorado, Jennie Myra (Albert Rice) and John Bradford- died young buried in Iowa.
1884 Julius moved to Knox Co., Nebraska - wife died and buried in Neb. Then Julius moved to Montana where his children Julia, Charles and James lived.
William remained in Boyd Co, Nebraska and Jennie in Valley, Neb. then she moved later to Portland Or
Julius died and is buried in Carter, Montana on 7 Feb. 1917
I hope this helps. I checked again in reference to Julius's mother, however I could not.
Happy New Year