In those days an important reason to leave was the bad economic situation in the homeland. The Napoleonic wars exhausted the country. The wars that caused separation from Belgium, the tax burden, the potato rot (1845-1847), and the consequent drought leading to extremely high food prices, caused bitter poverty in many parts of the country. Especially the working class had a very hard time. There was, however, another reason to leave.
Johannes (Jan) van der Kragt  was on military leave during his wedding on May 26, 1847 and later on became an inn keeper in Groenlo, like his father in-law. After the last mentioned passed away the family probably decided to emigrate to Canada, due to the promotion policy in those days.
According to Robert P. Swieringa; Nederlandse emigranten naar Verenigde Staten, Zuid Afrika, Zuid Amerika, en Zuidoost Azië, that contains names of people who emigrated, Johannes and his family travelled from Amsterdam to New York USA on the Trident. He was a baker at that time, according to the mentioned source in ARA, The Hague.
Ancestry.com, Dutch Immigrants to Amerika, 1820-1880 gives the following information:
Johannes Vanderkragt, date of arrival: May 15, 1850 New York, USA, destination unknown, age 26, male, profession: baker, relation: husband.
Ephemia Maria Vanderkragt, date of arrival: May 15, 1850 New York, USA, destination unknown, age 32, female, profession: housewife, relation: wife.
Theodore Anthonius Vanderkragt, date of arrival: May 15, 1850 New York USA, destination unknown, age 1, male, relation: son.
For each of them Amsterdam, Nederland, was mentioned as place of origin, they came to the US on the Trident.
These data come from microfilm Series M-237 and microfilm roll 88.
The list of emigrants in RA Gelderland gives the following details: profession 235, Roman Catholic, not wealthy, tax assessment 3. He probably brought a servant. According to Anna Matthijssen  the family probably got into timber business.
After several searches on the internet indications were found of their destination in the US.
Source: Woods’ Baltimore city directory 1867-1868:
Vanderkragt Mrs. Mary, tobacconist, 119 Eastern avenue
Euphemia Maria aged 51 at that time.
SHOULD ANYONE KNOW HOW TO FIND THEIR DESCENDANTS THEN I WOULD BE VERY PLEASED TO HEAR ABOUT IT!!!!!!!!!