Pictures shown are mature trees for sake of reference. 
This product is sold in transplant size bundles of 25.
(Not full grown)
 
Excerpt from The Morton Arboretum: https://mortonarb.org/plant-and-protect/trees-and-plants/black-walnut/
 
The black walnut provides excellent shade for large properties. It needs to be sited with care, since the tree produces a chemical that is toxic to some other plants. The fruit is a rounded, yellow-green husk containing a nut that is a food source for squirrels. The black walnut also attracts the banded hairstreak butterfly, serving as a caterpillar host. 
 
Family (English)Walnut
Family (botanic)Juglandaceae
Foliage: Deciduous (seasonally loses leaves)
Native locale: North America
Size range: Large tree (more than 40 feet)
Mature height: 50-75 feet
Mature width:30-50 feet
Light exposure: Full sun (6 hrs direct light daily)
Hardiness zones: Zone 4 - 9
Soil preference: Alkaline soil, Moist, well-drained soil
Tolerances: Alkaline soil, Clay soil, Occasional drought, Road salt
Shape or form: Round
Growth rate: Moderate
Transplants well: Yes
Planting considerations: Messy fruit/plant parts
Wildlife: Cavity-nesting birds, Game mammals, Songbirds