From Ohio History Central
The Fusion Party was the original name for the Republican Party in Ohio. The Fusion Party was formed in 1854. Many Ohioans opposed the Kansas-Nebraska Act of 1854. This legislation allowed the Kansas and Nebraska territorial legislatures to decide whether or not to permit slavery within the borders of their respective territories. Kansas and Nebraska were part of the Louisiana Purchase of 1803. The Missouri Compromise of 1820 stated that slavery was to be illegal in both Kansas and Nebraska. The Kansas-Nebraska Act set aside the Missouri Compromise and allowed for the extension of slavery.
Many Ohioans opposed slavery. Even more Ohioans did not want to compete with slave owners for land in the West. As a result of this dislike for slavery and the potential extension of the institution under the Kansas-Nebraska Act, several people met at a state convention on July 13, 1854. The abolitionists in attendance hoped that the conventioneers would condemn the Fugitive Slave Law of 1850. However, a majority of participants were more concerned with slavery's potential extension into Kansas and Nebraska. The delegates demanded that all future states admitted to the United States had to be free states.
Numerous other states in the United States held similar conventions during this period. Many of the participants in these other conventions adopted the name Republican to identify themselves. Ohio's conventioneers failed to adopt this name. Instead, they become known as Fusionists. The name was given to them by their opponents, because the meeting's participants were a fusion of people from numerous different political backgrounds. Many of the participants were members of the Free Soil Party, the Conscience Whig Party, and the Know-Nothing Party. A number of members of the Democratic Party opposed to slavery's expansion also joined the Fusion Party.
The Fusionists made major gains in the election of 1854. In 1855, the party's delegates met in Columbus to select a candidate for governor. It was at this convention that the Fusion Party formally became the Republican Party in Ohio.