I can believe it. If Rabbi Wise was telling the truth then there's a confirmation.
One of the commenters humorously mentioned Judah P. Benjamin. Reading
The Secret Relationship Between Blacks and Jєωs, which used entirely Jєωιѕн sources, it's apparent that the architects of the trade were Jєωιѕн, and that whites were minor players, probably even more minor than black participants. The Atlantic Slave Trade benefited whites the least.
https://reformjudaism.org/blog/2016/02/11/was-abraham-lincoln-member-tribeOn the twelfth of February, 1809, slightly more than 200 years ago, a young, poor illiterate woman from Virginia, Nancy Hanks Lincoln, gave birth to a son in a log cabin built along the banks of the south fork of Nolin Creek, near what is now Hodgenville, Kentucky. That baby, whom she named Abraham, grew to become one of our greatest, and most tragic, national leaders.
Lincoln was a man of great spiritual conviction. Yet – and I find this fact fascinatingly instructive – Abraham Lincoln is the only American president not to have declared himself a member of any particular religious faith. That fact has given rise to a great deal of interesting speculation. In fact, there are those who believe that Honest Abe was Jєωιѕн.
After all, his name was Abraham. His great-grandfather was named Mordechai. Lincoln was the only president not to have a formal religious affiliation. He was neither raised in a church nor did he ever belong to a church.
There's more...
The town of Lincoln, in eastern England, whence his ancestors came, has an interesting Jєωιѕн history. A Jєωιѕн community was established there in 1159. During Crusader riots, the Sheriff of Lincoln saved the Jєωs by giving them official protection. St. Hugh, the great Bishop of Lincoln, taught love of Jєωs to his parishioners. His death was marked by an official period of mourning among Lincoln's Jєωs.
Rabbi Joseph of Lincoln was a scholar mentioned in the тαℓмυd; Aaron of Lincoln was a financier whose operations extended all over the country. In 1255, Lincoln's Jєωs were accused of ritual murder. Ninety-one Lincoln Jєωs were sent to London for trial and 18 were executed. Notwithstanding, the Lincoln Jєωιѕн community flourished until 1290, when its members were forcibly expelled by edict.
Most Jєωιѕн historians assume that all the Jєωs of Lincoln left in 1290. But is it possible that some remained, practicing their Judaism in secret... passing the family secret from generation to generation? The more we learn of the secret life of Spanish Jєωry following the expulsion of 1492, the more we must at least consider the possibility that the same thing occurred elsewhere.
When Abraham Lincoln was αssαssιnαtҽd, whole Jєωιѕн communities sat shiva. Rabbis all over the country eulogized the fallen president. Rabbi Isaac Mayer Wise, the man who created Reform Judaism in this country, began his eulogy with the words... "Brethren, the lamented Abraham Lincoln believed himself to be bone from our bone and flesh from our flesh. He supposed himself to be a descendant of Hebrew parentage. He said so in my presence."
Lincoln was often questioned about his religious beliefs. Time and again, he told of a special passage from Scripture that summed up his theology. It was the 20th chapter of the Book of Exodus he recommended that every American study, learn and follow. In English it is usually referred to as the Ten Commandments.