* Highest total enrollment: This would likely be in the most populous states (e.g., New York, Pennsylvania) or possibly in a country with a larger overall population. However, accurate enrollment data from 1860 is patchy at best, particularly for less developed areas or those with less centralized record-keeping.
* Highest enrollment rate (percentage of population enrolled): This would be a different measure and might favor states with different demographics or levels of educational investment. Some states might have had a higher percentage of children attending school than others, even if their overall numbers were lower.
Without access to comprehensive, reliable 1860 enrollment statistics across all geographic locations, a definitive answer isn't possible. Further research using historical census data and educational records would be needed.