Actually, Thomas Blossom was a Mayflower Pilgrim. However, he arrived on a later ship, also known as the Mayflower, in 1629. Most of the passengers on this trip were those who had intended to arrive in 1620 with the first Pilgrims. However, Blossom and his fellow passengers had been on board the Speedwell, which turned out to be so leaky and unseaworthy that it was forced to turn back before the voyage was well underway.
Thomas Blossom was born about 1580, probably in Great Shelford, Cambridgeshire, England, the son of Peter and Annabel Blossom. Her maiden name is as yet unknown. He was the youngest of four children; a fifth, Francis, Peter and Annabel's first born, had lived only about a month. As the youngest child, he may have been pampered just a little bit, and he seems to have secured an education somehow. His later letters to William Bradford are not those of an uneducated man.
There isn't much known about Thomas's life as he was growing up. His father was described as a husbandman and then a laborer, so he may have fallen upon hard times before he died in 1597. Thomas married Ann Helsden or Elsdon on November 10, 1605 in St Clement's Church, Cambridge, England. (The church is still in existence and can be googled for interior views; however, it appears that the church bears little resemblance to the building of 1605.)
I'm not sure when Thomas would have acquired his Puritan views. Most families that went to Leiden in 1609 had been Puritans for years, so perhaps Thomas and Ann had held their beliefs for years, or perhaps they were "late" converts. Regardless, in 1609, the couple were in Pieterskerkhof, Leyden, Holland with the Separatists, and several children were born there. The first two children died before the 1620 trip, and another son was born before 1620 and died in 1625. Elizabeth, Thomas, and Peter were born in Leyden and accompanied their parents when the trip to Plymouth was finally accomplished in 1629.
Thomas was a deacon in the church at Plymouth Colony, but little else is known of him there. He died of an infectious fever in 1632, along with at least 19 other colonists. His widow was taxed 9 shillings in 1633, which seems to be the minimum amount that anyone was assessed. Ann married Henry Rowley on October 17, 1633.
Most of the information for this post came from a Robert Charles Anderson article called "Pilgrim Village Families Sketch" found on americanancestors.org, and from a book called "Plymouth Colony, Its History and People 1620-1691" by Eugene Aubrey Stratton.
The line of descent is:
Thomas Blossom-Ann Helsdon
Elizabeth Blossom-Edward Fitzrandolph
Nathaniel Fitzrandolph-Mary Holley
Samuel Fitzrandolph-Mary Jones
Prudence Fitzrandolph-Shubael Smith
Mary Smith-Jonathan Dunham
Samuel Dunham-Hannah probably Ruble
Jacob Dunham-Catherine Goodnight
Samuel Goodnight Dunham-Eliza Matilda Reese
Margaret Catherine Dunham-Harvey Aldridge
Cleo Aldridge-Wilbur Beeks