He was born in Kil, Sweden as Gustaf Rudolph Thomas Wilehmsson to Farjunkare (Sergeant Major) Thomas Wilhelm Halck b. Malmo, Sweden and Ingeborg Andersdotter b. Kola, Sweden. . Although Thomas Wilhelm's son, Gustaf, according to parish records was born with the last name, Wilhelmsson. Two parish records show the spelling his father used as "Halck and Halk". However, Gustaf's migration record to Norway and the marriage record in Olso show the spelling as "Halek". He may have changed his last name from Wilhelmson to Halek when he went to Norway. Gustaf Rudolph Thomas Wilhelmson (Halck) married Hannah Olsen of Bohuslan Sweden Kville Sweden b 1 Feb 1846. They married in Oslo, Norway 20 Sept. 1874 (under Johanne Mortana Olsen...father Ole Olsen) where they had their first child, Hannah Halck. When their child, Hannah, was two years old they came to America and lived at Cornwall on the Hudson, New York State. From there they went to Chicago where they opened a grocery store at 5918 Aberdeen St. and had four more children. Hannah passed in Chicago Il from diabetic complications Mar 22, 1889. Gustaf (Gustave) re-married Ida Mary Carlson. According to "The Englewood Economist Obituary Oct 10, 1958" Gustaf was in the cigar business and later dealing in trunk and leather goods on 3rd St., Chicago, IL.

Gustaf had 2 sisters and 3 brothers:
- Hilda Christina Wilhelmsdotter b. 16 Oct 1818 Grava, Sweden
- Gustafva Emilia Wilhelmsdotter b. 28 July 1846 Kil, Sweden d. in Olso, Norway just prior to WWII
- Albert Theodor Wilhemsson b. 11 Apr 1848 Kil, Sweden
- Johan Wilhelm Wilhemsson b. 6 Dec 1849 Kil, Sweden
- Oscar Emil Wilhelmsson b. 1 Nov 1852 Kil, Sweden d. 5 Dec 1857 @ 5 years old in Strommestad, Sweden

Hannah and Gustaf had five children:
Hannah
Herbert (never married)
Henry (never married-estate settled in 1945)
Lulu
Alice Yerda (passed @ 12 years of age)

Gustaf Halck remarried Ida Carlson of Sweden. They had one daughter, Irma Halck, who's married name was Hanneman.