Since there was slavery in the Americas between their discovery and 1865, do we know of any Jewish slave-owners there who observed slavery-related laws of Judaism?
From a conversation with Eli Faber (A professor of history at John Jay College in New York and author of Jews, Slaves and the Slave Trade: Setting the Record Straight):
The only thing I have encountered is a description of how, in Jamaica, the Jewish slave owner gave his slaves all of Saturday (Shabbat) as well as Sunday off. This was very significant because in Jamaica (I believe unlike in the eventual US), slaves were permitted to work parcels of land and sell the produce at markets. Accordingly, the slaves of Jews were able to plant more, sell more, and earn more money than those owned by non-Jews, who gave their slaves only half a day off on Saturdays, as well as Sundays. For my reference to this, as well as the source in which I found it, see the book I wrote, "Jews, Slaves, and the Slave Trade: Setting the Record Straight," page 62. Jews in Jamaica thus adhered to the Biblical prescription that slaves, servants, etc., were to be able to rest on Saturdays, too; see the fourth of the Ten Commandments ("Exodus," chapter 20). The owners in Jamaica clearly adhered to this Biblical command---though the slaves reportedly chose to work on Shabbat.
Based on his extensive research into the matter, I think we can conclude that this was the extent that Jewish slave owners observed slave-related commandments in the Americas.
Slaves were kept in the Caribbean by Jews and according to some estimates, Jews controlled ~20% of the Dutch slave trade. Remember that these Dutch-colony Jews were of Sephardic descent and spoke Judeo-Portuguese/Spanish as well as Portuguese and Dutch. This book, Berit Yitzchaq was published in 1768 (this particular copy is from Suriname). The 1768 edition is available on Hebrewbooks.
It was also published in 1729, with a slightly different text, though the preface to that edition indicates that the text is fairly old, having originated in the Holy Land and come through the Ottoman Empire to the Netherlands. However, that edition did not contain the circumcision rites.
The 'Torat Ha-adam' section of the 1768 edition contains the circumcision rites, for all kinds of circumcision [living parents, dead father, etc.]. It also contains a section for the circumcision of slaves with the title "סדר מילת עבדים וטבילתן בזמן שבית המקדש היה קיים" "the order of circumcision and immersion that was done when the Temple stood".
This introduction is strange to say the least. It is unclear if this was a tactic for hiding or disapproving of the institution of circumcizing slaves, or whether it was a text that sought to justify modern slavery.
Other scholars have pointed out that in Curaçao the Jews did consider their slaves Jewish and circumcised them, while in Suriname they did not. However, both communities would have likely used the same prayer books printed in Amsterdam. There is some evidence that the organizer of Berit Yitzchaq had family in Suriname who did not circumcise their slaves.
It should be noted that as seen in the register of mohalim (licensed circumcisers) printed in the back of the book, there were more mohalim (or at least more mohalim recognized by the Dutch Sephardic community) in Suriname and Curaçao than in London, Naarden, Haia, Hamburg, and Bayonne combined.
However, it seems unlikely that the circumcision of slaves was widely practiced, even among slave-holding Jews. As far back as the Talmudic period, a category of “uncircumcized slaves” existed, with unique laws. This was especially important for the purpose of allowing slaves to work on the Sabbath, as circumcised slaves are required to observe the Sabbath the same as Jews. The important Sephardic rabbis of the 12th and 13th centuries, Maimonides and Nahmanides, both dealt extensively with the category of “uncircumcized slaves”, quietly advocating the end of circumcision. Ashkenazic (Jews of German/French/Polish origin) Jews would buy slaves on condition that they not be circumcised, thus de facto abolishing circumcision. It is highly unlikely that Dutch Jews would have reinstituted the practice on their own.
So were Slave-related commandments practiced in America? Mostly not. But for some time in the 18th century in the Dutch colonies, they may have been.
For those interested in the picture, it is from an exhibit at the Princeton University Art Museum http://artmuseum.princeton.edu/art/exhibitions/1655. (Maduro, S. (1768). Berit Yitzhaq. Amsterdam: Jansen Family Press. (From the private Judaica collection of Leonard L. Milberg. Currently on display in the “By Dawn’s Early Light” exhibition in the Princeton Art Museum.))
For more information on Jews and slavery in the Caribbean see Paths to Freedom: Manumission in the Atlantic World p. 83
There's a lot of work on the history of Jews and their "slaves", but from a halachic-history perspective, see * The Shabbes Goy: A Study in Halakhic Flexibility* by Jacob Katz
My rav says he heard (can't remember from where) that many of the black Jews in B"SD America are descended from manumitted 'avdei kena'anim. I think there was a Moroccan Jew by the name of Lewi (Levy?) who lived in the southern part of the USA then & they may be his freed slaves (there were Jewish slave owners in N. Carolina as well). These dinim are from M. Yevamoth. Jews are NOT allowed to own stam slaves. A gentile slave can have a trial period w/a potential Jewish owner for 30 days, but he must then decide if he wants to leave his gentile master & convert into a kena'ani slave who will then be obligated in the same dinim that Jewish women are obligated (kashruth, shabbath, etc.). If he opts in, his giyur is done in such a way that he will not be able to speak just before, during & after his immersion so that he doesn't announce that his giyur is not for 'avduth, but for complete Yahaduth (in such a case, he'd be a full geir & NOT a slave, but he'd OWE his value as a slave to his former master & there is such an incident as that in M. Yevamoth in Bavel). A 'evedh kena'ani's slavery is a tiqun for him. R. Eli'ezer holds for giyur in general MILAH is enough. If a gentile wished to convert, performed milah, but DIED before his immersion, then he's buried in a Jewish cemetery. Who, then, is more "Jewish?" Such a man or an 'evedh kena'ani (who we say is NOT exactly Jewish!)?
Slavery related laws that I'm aware of, refer to Jewish slaves.
There are two types of slavery regarding Jewish slaves. One is when one kidnaps a person and enslaves him. I just happened to read in this week's parsha Ki Seitzei 24:7 "If a man is found kidnaping a person of his brethren among the children of Israel, and he enslaves him and sells him, that kidnaper shall die, and you shall remove the evil from your midst."
The other is in Parshat Mishpatim when a man is in debt and pays off the debt through slavery. That is where all the slavery laws I know of are listed. Regarding how to treat him, how and when to release him etc. Does not have relevance to slavery in Americas.