Final answer:
Delegates from 18 states attended the first national convention of the Future Farmers of America (FFA) in 1928.
Step-by-step explanation:
The first national convention of the Future Farmers of America (FFA) in 1928 was represented by delegates from 18 states. The FFA organization was created to support agricultural education in the United States, and its inaugural national convention marked an important milestone in its history. Although earlier local and state gatherings of agricultural societies occurred, the 1928 national convention is recognized as the birthplace of the national FFA organization.