[1] A large body of work between 1968 and 1975 includes paintings and drawings such as Two Different Horizons (1971), Night Watch (1971), and Final Farewell (1975) depicting Captain Alexander Breede (d. 1971), a retired seaman.

His work was shown in museums and galleries including the West Virginia University Creative Arts Center and the Westmoreland Museum of American Art, drawing interest from collectors and commentators including Paul A. Chew, a former director of the Westmoreland, and George Nama, an artist and teacher of draftsmanship and printmaking at the University of Pittsburgh.

[10][11][9][12] In a critical essay, Chew wrote: "It is gratifying to see David Hanna develop a personal, stylistic interpretation of the American tradition of realist painting that has been established by some of our greatest artists—Winslow Homer, Thomas Eakins, and Edward Hopper.

[15][16] During the 1970s, Hanna also contributed works to a 1973 book titled The White House Gardens: A History and Pictorial Record with commentary by Rachel Lambert Mellon, often known as Bunny Mellon, a renowned horticulturalist, gardener, and art collector whose family owned a number of Hanna's works.

[17][18] The exhibition "David Hanna: Paintings, Watercolors, Drawings", organized in 1977 by Chew at the Westmoreland Museum of American Art, featured 78 artworks including depictions of Hanna’s children such as A Million Miles Away (1971), the architecture and furnishings of his native Pennsylvania, and the landscape, buildings, and inhabitants of Maine and other New England states, such as The Keith House (1974-1975).