At the conclusion of July 3, 1863, Dr. Michael Jacobs noted dryly in his weather record, “The thunder seemed tame, after the artillery firing of the afternoon.” Of course, the artillery barrage of that afternoon was likely the largest that had occurred in history to that point. Similarly, the thunderstorm was a prelude to a deluge over the next day and a half that flooded creeks and rivers, drowned wounded men, and made the rest of the wounded utterly miserable in the places where they were being treated.

Dr. Jacobs became renowned for his weather observations that helped researchers understand the atmosphere of the battle as well as that of the days before and after (the torrential rains that followed the battle had a huge effect on Meade’s pursuit of Lee’s army). For years, researchers weren’t totally sure why Jacobs had made his observations and where they wound up. They were cited by his son and others in the decades that followed the battle, but the originals were missing for decades. Jeff Harding has tracked down the originals, and in doing so, he helped researchers understand why Jacobs kept his records—Jacobs had joined a group of researchers who recorded their weather observations throughout the country in what became a precursor of the National Weather Service.

By 1863, Jacobs was 55 years old. He had been a professor, theologian, and teacher at the Lutheran Theological Seminary and Gettysburg College for thirty years. He was an ordained minister who preached at the Lutheran Christ Church on Chambersburg Street. His closest brother David had also been a reverend and teacher and had brought Michael with him to Adams County to work in the seminary and school. He was a prolific researcher and writer on many subjects. He invented a process for canning food, then later presented a paper at a scientific society entitled “Indian Summer.” He wrote articles on theology for the Evangelical Review and articles on science for Linnaean Record and Journal. Being so well versed in theology, history, and science, he was keenly aware of the historical importance of what was happening around him. At the opening of the battle, he was teaching but abruptly dismissed class, noting to the students that their minds were clearly not on their studies.

He returned to his home on the corner Middle Street and South Washington Street (the home still stands today and is marked with information about Jacobs and his family). There, he rode out the battle until July 3. When the massive cannonade wound down, he went back upstairs and instructed his 14-year-old son Henry to go with him, saying, “Quick! Come! Come! You can see now what in your life you will never see again.” In doing so, Dr. Jacobs gave the observant Henry a chance to observe Pickett’s Charge.

Within the next year, Dr. Jacobs wrote the first book about the battle, which was published by Lippincott: Notes on the Rebel Invasion of Maryland and Pennsylvania and the Battle of Gettysburg, July 1st, 2nd and 3rd, 1863. The title was well regarded, and Jacobs felt obligated to supply a copy to Abraham Lincoln himself. His letter to Lincoln was kept in the Lincoln papers and is today in the Library of Congress.

The circumstances of his life are challenging at points, curious at others. He was the youngest of eight and would not have remembered his mother who died when he was just 18 months old. His father died when Michael was only 13; he was almost certainly raised by his siblings and heavily influenced by his closest brother, David, who brought him to Gettysburg and to the profession he would serve in the rest of his life. He married Julia Matilda Eyster at age 25, but the couple had no children for 16 years, after which they had three boys and one girl.

Dr. Jacobs was well regarded around town—Dr. J. Lawrence Hill counted him as a friend and regularly listed him as a reference in his dental advertisements. The local newspapers regularly noted his doings.

In June 1871, Dr. Jacobs passed away, leaving behind his wife and all four children. Juliana outlived him by more than 20 years, and his children lived well into the twentieth century.