Gray began to become moderately wealthy and expanded his business interest into grain processing and banking. He was one of the founding members of the Citizens Bank in Union City in 1865. He continued to be interested in politics, and decided to run for public office. He had been a Whig before the party collapsed in the mid-1850s, and decided to become a Republican following the war. In his first run for office, he competed against George Washington Julian in the Republican primary, hoping to become a candidate for Congress, but was defeated in 1866.
