Before 1700, two families of New Netherland bore the Dyckman name. Here we will discuss the relationship between the two.
Family #1 - Johannes Dyckman, son of Joris (George) Dyckman of Amsterdam, Netherlands. Johannes came to Fort Orange (Albany) in 1651, as a clerk and commissary for the Dutch West India Company. He had two sons: Johannes Dyckman, Jr., and Cornelius Dyckman. Cornelius married Rachel Deveux, granddaughter of Daniel Tourneur via his daughter, Hester (or Esther) Tourneur.
Family #2 - Jan Dyckman, who arrived at Harlem about ten years later, in 1661. Jan married Magdalena, daughter of Daniel Tourneur, on June 15, 1673. Upon the nuptials, Tourneur gave the newlyweds two out garden plots and a farming plot on Montagne's Flat. The Dyckman Farmhouse, which still stands today on Broadway in Manhattan - the oldest house in Manhattan, built in 1764, belonged to his line. Was it the land given to Jan by Daniel Tourneur?
Therefore, in summary, Rachel (Deveux) married Cornelius Dyckman in 1702. Her Aunt Magdalena had also married a Dyckman, but the two branches are unrelated as far as we know. The first name of both Jan and Johannes, are forms of the English name John. Therefore, it's safe to assume Johannes and Jan weren't brothers.
By the end of the seventeenth century both families had Dyckman baptisms and marriages in the Reformed Dutch Church of New York and into the 1800s, both families were found in Harlem, causing some confusion among genealogists.
A book by H. Romer and Helen Hartman in 1891, called "Jan Dyckman of Harlem and his descendants", provides important information necessary to distinguish between the two branches, and much information about Jan's line. Jan's branch is described as the Kingsbridge Dykemans and Johannes' branch is referred to as the Albany family or the Bloomingdale Dyckmans because Cornelis of Harlem made his home at Bloomingdale - collectively the Joris (George) Dykeman group. The book can be "borrowed" (free) on Archive.org, providing it is available. (You may have to join the waiting list to access it).
Visit the farmhouse's website at dyckmanfarmhouse.org. Virtually visit the Dyckman Farmhouse on Google Maps:
Jan Dyckman of Harlem and his descendants, by H. Romer and Helen Hartman, 1981.
Viele Records, 1613-1913, being a revised and enlarged edition of the Viele Genealogy published in 1909, under the title "Two hundred and fifty years with a Dutch family of New York", by K. K. Viele, 1913.
Dykeman House photo from D.A.R. Magazine