William was born Willem Dijk in the country village of Thesinge, municipality Ten Boer, located in the mid-north of the Dutch northeastern province Groningen. His parents are Jan Dijk and Fijlina van Dijken.

On 21 March 1904 William's parents farmer Jan Dijk (48 years old) and Fijlina (47) arrived with their seven sons, Pieter (22, farmer), Jan (17, farmer), Arend (14, farmer), Willem (12), Lambertus (9), Hendrik (7) and Harm Pieter (6) on the SS Potsdam at Ellis Island, New York. Their last residence place in the Netherlands was Thesinge and their destination is Fijlina's brother P. van Dijken in Gallatin Valley, in the southwestern part of Montana.

In 1910 William Dyk lived with his father, since March 1909 widower, and five brothers in the Heeb School District of Gallatin County.

On January 14, 1915 William Dyk married at Manhattan, Gallatin County, at the age of 23 years to the three years younger Jennie Boss, daughter of E. Boss and Jennie Sniet and who was born at Manhattan.

In 1920 William (28 years old) and Jennie Dyk (25) resided with their children Fylena (4), Jennie (2 y 10 m), John (1 y 9 m) and Anna (7 m) in Gallatin county too. Jennie's father Egbert Boss (54) lived with them.

In 1930 William (38) and Jennie Dyk (35) resided with their children Fylena (14), John (11), Anna (10), Egbert (9), Herman (8), Dora (7), Theresa (5), Arthur P (4), William (3) and Jennie (1) at Manhattan in Gallatin county too. Jennie's father Egbert Bos (64) lived with them.

In 1940 farmer Wm (48) and Jennie Dyk (46) resided with their children Fylena (24), John (21), Anna (20), Egbert (19), Herman (18), Dora (17), Theresa (15), Arthur P (14), William (12), Joan (10), Marie (9) and Arnold Ray (6) at an own farm, worth $1600, at Manhattan too. Jennie's father Egbert Bos (74) lived with them. In 1935 they lived in the same house.