The Costine Law Firm was established in 1920 by John E. Costine 1894 -1954. Ancestors immigrated to the United States from the Welsh Isle of Mann during the 1860s. John E. Costine was an avid baseball fan and played with the Ohio Valley Athletic Club, a local touring team. He provided counsel to many immigrating families in particular the Italian-American community because the surname Costine was often thought to be Italian in origin (Costini). John E. often sought the aid of interpreters in various european languages.

Son, John O. Costine joined his father in the practice of law in 1952. This dual father/son partnership quickly closed with the death of John E. in 1954. John O. continued the practice focusing his efforts in the area of probate, real estate and tax law. John O. Costine's naval experience provided him with a love of small boat sailing which has continued to the present.

J. Mark Costine joined his father, John O. in 1980. Mark brought a sense of expansion to the firm by including criminal and civil trial work, an area of experience which was not growing in Belmont County during the years of John E. and John O. Costine. Mark left the firm in 1998 to assume the position of Belmont County Common Pleas Court Judge-Probate Division.

In 1985, Eric Costine entered the law firm and joined his father and brother as the third practicing attorney in the office. Eric's scholastic achievements spanned his interest in English and Philosophy while his extracurricular activities involved other avenues. His interest in photography, which developed in high school, and his love for music, from artists like Bob Dylan & Frank Zappa, blossomed over his years. Eric has also been captivated by travel and fueled this desire by completing the bicycle trek of the Tour of Scioto River Valley (TOSRV) twice in 1980 and exploring cultures in at least twelve different countries. Eric has also explored a passion for computers and computer technology by being an avid user of a variety of cutting-edge computer systems.

In 1999, Kevin Bench became the newest member of the Costine Law Firm. Kevin has recently taken the Ohio Bar Examination and is licensed in the State of Ohio. As a graduate of Linsly School in Wheeling, West Virginia, Kevin has explored cultural interests involving overseas travel to countries such as Germany, Sweden, Austria, and Switzerland. Kevin's scholastic interests have revolved around Political Science, History, Philosophy, but his main passion has been music and movies. Kevin has also explored different foreign languages, such as German and Latin and has attempted to maintain his level of language proficiency by living at college at Miami University of Ohio on a German - speaking corridor for three and one - half years. Kevin also enjoys weightlifting and spending time with his friends and family.