I am also researching this family. Julia's sister, Elizabeth, married Johann Heinrich Schulte, my husband's great-grandfather. I have the following info on John A. Fischer. I'd love to share more info with you!

HISTORY OF KENTUCKY AND KENTUCKIANS, E. Polk Johnson, three volumes, Lewis Publishing Co., New York & Chicago, 1912. Common version, Vol. III, pp. 1272-73. [Kenton County]
John A. Fischer invented and had patented the Family Fire & Burglar Proof Safe, which he manufactured and sold extensively during his life-time, and which is still manufactured and forms no small business of the present company. He is a native of Germany, the date of his birth being 1846. He was but ten years of age at the time of his emigration to the United States. He made the journey alone and proceeded directly to Ludlow, Kentucky, where he joined relatives. While crossing the Atlantic he lost his hat and was compelled to finished the trip bareheaded. He secured employment in a dry-goods store at Ludlow and when fourteen years of age entered upon an apprenticeship at the locksmith's trade, being identified with this occupation for a number of years. In 1872 he entered into a partnership alliance with William Bogen Schutz, and they began business as locksmiths in the city of Covington. This enterprise proved disastrous and Mr. Fischer was soon working at his trade again as a journeyman, and it was during this period that he patented his safe. In 1884 he laid the foundation for his future success as a hardware merchant and through fair and honorable methods he built up a fine thriving business, the same being now carried on by his heirs. He was summoned to the life eternal at Covington, in 1892, at the age of forty-six years. His death was the result of injuries received from an accidental from a building in process of construction. He was a large-hearted, broad-minded man,
deeply interested in all matters pertaining to the general welfare and he was held in high esteem by his fellow citizens. He married Julia Monning, a native of Ironton, Ohio, and they became the parents of twelve children, eleven of whom are now living. Mrs. Fischer survives her honored husband and she now resides at Covington, much beloved by all who have come within the sphere of her gracious influence.