Slack family coming to America

James Burns Slack (grandfather of James Slack Parker) came to the United States on the Ship George Washington, arriving in Boston on April 20, 1857. He came with a large group of Latter-day Saints who were headed to Salt Lake City, but he did not join them. He stayed to work in Boston. James wife, Mary Jones Slack, and their daughter, Harriet Slack, came to America on the Ship John Bright a year later, arriving in New York on April 23, 1858. Mary and Harriet are not listed on the Mormon Migration list of passengers (probably because they were not traveling to Salt Lake with the mostly Scandinavian company that was on the John Bright). However, below is a snippet from the John Bright ship manifest with Mary Slack and Harriet Slack listed (lines  35 and 36). They are 2 of the 9 passengers on board that were from England (from Mansfield, Nottinghamshire, England).

In 1859, Mary's mother and sister, Mary Mitchell Jones and Harriet Jones, arrived on the Ship Antarctic in New York on August 21, 1859.

I would imagine that all of these relatives met up and probably lived in Boston and worked and prepared for the journey to Salt Lake City. They did not leave for Utah until 1861, so they had a little bit of time to be together before their journey west.