The romantic comedy classic “It Happened One Night,” produced and directed by Catholic filmmaker Frank Capra, was released in a significant year in Hollywood history: 1934 saw the rise of the National Legion of Decency (founded the year before as the Catholic Legion of Decency) and the beginning of the era of the Production Code Administration (PCA) — a period often criticized for strict censorship, but also celebrated as Hollywood’s Golden Age.

The PCA was Hollywood’s effort at moral self-policing to appease critics and ward off government oversight. It was commonly known as the Hays Office, the Code itself as the Hays Code — misleadingly in both cases, masking the Catholic influence in Hollywood. Will Hays was a Presbyterian elder hired in the 1920s to clean up Hollywood’s image. Few knew the Production Code was written by a Jesuit priest, Daniel Lord; it was also run from 1934 to 1954 by a Catholic layman, Joseph Ignatius Breen.

In 1934, then, the sometimes comparatively risqué “pre-Code” era was over, and a new era of propriety and decency was in place — though filmmakers often found creative ways to bend the rules and get their point across.

“It Happened One Night,” new on Blu-ray from the Criterion Collection, offers the perfect metaphor for this new situation: the “walls of Jericho,” as Clark Gable ironically dubs the sheet he hangs between twin beds when he and Claudette Colbert are obliged to share a room while posing as man and wife.

The sheet is a flimsy barrier, easily circumvented, but depending on Gable’s integrity rather than its intrinsic strength to protect the lady’s honor. “Maybe not as thick as the ones that Joshua blew down with his trumpet,” Gable jokes, “but a lot safer. You see … I have no trumpet.” Only after the madcap finale, with Gable and Colbert married for real, is a trumpet blown and the “walls of Jericho” come tumbling down.

Another Capra classic, “Mr. Smith Goes to Washington,” debuts on Blu-ray next week from Sony. Like Capra’s later “It’s a Wonderful Life,” which of course also starred Jimmy Stewart, “Mr. Smith” is both a celebration of the impact a single heroic person can have and a cautionary tale about the dark side of the American dream.

If “It Happened One Night” invokes the Old Testament story of the battle of Jericho, “Mr. Smith” plays (as a member of the community once noted) as a kind of American passion play, with Stewart’s Jefferson Smith as an innocent Christ figure confronting the sins of Washington, DC, facing his dishonest accusers in silence, opposed by the public that once embraced him, and enduring an excruciatingly prolonged ordeal to combat evil before collapsing in a dead faint.

There is also a Judas figure, Claude Rains, who plays a close friend who betrays the hero before succumbing to remorse, proclaiming the hero’s innocence and attempting suicide (if not quite in that order).

Both Capra classics come to Blu-ray with new 4K digital transfers, looking better than they have since their theatrical debuts. Among the generous bonus features in both sets is one shared extra, the 96-minute 1997 documentary “Frank Capra’s American Dream” narrated by Ron Howard. Other extras for “It Happened One Night” include a new 40-minute analysis of the film by critics Molly Haskell and Phillip Lopate; “Mr. Smith” comes with a commentary by Frank Capra Jr.