Lambertus Witvoet (= White foot) was born in March 1871 in the country village of Grootegast, in the western part of the Dutch northeastern province Groningen, the third child and second son of farmer Gerrit Witvoet and Geertje Aardema, who had ten children.

He had in Grootegast the following nine siblings:
* Jantje, 8 June 1866;
* Fokke, 24 February 1869;
* Neelina, 20 April 1872;
* Bastiaan, 16 June 1874, died 30 August 1881, Grootegast;
* Aaltje, 4 December 1876;
* Jan, 29 October 1879;
* Iwina, 4 October 1881;
* Bastiaantje, 6 March 1885;
* Anna Fokkelina, 2 August 1888.

His father Gerrit Witvoet was in 1866 a day-laborer, in all the other, later years farmer.

In 1892 Lambertus Witvoet (21, no occupation, Dutch Reformed) emigrated in 1892 from Grootegast to North America. He arrived on 13 April 1892 on the ship Didam at the port of New York, Castle Garden. His destination was Hammond, Lake County, Indiana. His brother Fokke Witvoet (24, no occupation) and sister Neelina Witvoet (20, no occupation) followed in 1893. Laborer Fobbie [!] and Nelesan [!] Witvoet arrived on 19 April 1893 on the SS Maasdam at the port of New York, with as destination Bozeland [??; has maybe to be: Bozeman, in Montana, seat of Gallatin County?]. On 26 August 1893 his father Gerrit Witvoet (58 y, farmer), his mother Geertje (48), his siblings Aaltje (16), Jan (13), Irviana (11), Bastiaantje (8) and Anna (4) arrived on the SS Rotterdam at the port of New York, Ellis Island. Their destination was the Dutch truck farmers settlement of Roseland, since 1892 a southern district of Chicago, Cook County, Illinois. In 1897 his sister Jantje Witvoet emigrated with her husband, smith Wobbe van der Veen and their three children Wiebren, Gerrit and Fokke van der Veen, from Marum, Groningen, to North America. With that the whole family Witvoet had emigrated to the USA.

In June 1900 Bert Witvoet (28 y, born in March 1872 [has to be: March 1871] in Holland, immigrated in 1893 [has to be: 1892], day-laborer), his wife Jennie (22, November 1878, Illinois, 2 y married, mother of one living child) and their daughter Esther (1, August 1899, Illinois) were living in a rented house at 103rd Street in Hyde Park Township, in the -southern- Ward 34 of Chicago, Cook County, Illinois.

On 3 November 1900 Lambertus Witvoet was naturalized by the County Court of Illinois, very probably located in Chicago.
The day before, 2 November 1900, his brother John Witvoet and father Gerrit L. Witvoet were naturalized by the same court.

In 1920 Berth Witvoet (49, immigrated in 1892), his wife Jane (42), their children Asten (20), Genett (17, Illinois), Herman (14, Illinois), Gertrude (11, Illinois), Jeanett (9, Illinois), John (6, Illinois), Albert (3, Illinois) and Fred (0, Illinois) were living at their own home in Thornton Township, not unlikely in or near the Dutch truck farmers settlement of South Holland, just south of Chicago, Cook County, Illinois.

Bert Witvoet remarried Minnie Klooster, since July 1912 widow of Adriaan aka Andrew Vander Pol.

In 1930 Bert Witvoet (59, immigrated in 1878 [has to be: 1892!]), his [second] wife Minnie (61, Holland, immigrated in 1887), his children Gerrit (27), Janet (20), John (16), Albert (13) and Fred (10) were living in Bloom Township, located south of Thornton Township and Chicago, Cook County, Illinois.

In May 1940 Lambertus Witvoet (69, farmer), his wife Minnie (71) and their son Fred (20, junk man) were living at their own farm in Bloom Township, Cook County, Illinois. In 1935 they lived in the same house.

His wife Minnie died in December 1948 at the age of 79 years in Lake County, in the utter northwestern part of Indiana. Widower Bert Witvoet died in 1956 at the age of about 85 years in Cook County, Illinois.