In 1856, Beach started his career learning business from his father and brothers, and sold his coal business to Capt. John Hendrick, the oldest in the city. At the death of his father in 1868, he inherited the Beach estate, including his father's
Italianate mansion built in 1846 at a cost of $62,000, or about 50 million dollars in 2024 money in relation to income. The house was built by architect
Henry Austin with the contractor and laborers brought from Italy, and had 16 bedrooms. Beach started his real estate ventures by created four streets in Wallingford, being Church, Meadow, Orchard and William streets, and built a housing development on the land he inherited. In 1871, he built a banking house between the corner of Main and Academy streets. From 1875 to 1876, William Yale Beach's private bank is recorded as the most important bank in
Wallingford, and is among the 52 largest in Connecticut by territories. ==Later life==