He built Tudor City, a housing development on Manhattan's East Side, for the rising middle class in the 1920s. He also developed Knickerbocker Village, middle-class housing on the Lower East Side between the Brooklyn Bridge and the Manhattan Bridge. His original intention for the project was to build housing for "junior Wall Street executives". His Fred F. French Building is a well-known skyscraper on Fifth Avenue in Midtown.

French and his company served as the developer and landlord of Knickerbocker Village, important in the history of landlord–tenant law. When the tenants were to take possession of their apartments, they found conditions to be unlivable. Facilities were either unfinished or poorly equipped, including non-working elevators and inoperable laundry rooms. The tenants formed the Knickerbocker Village Tenants Association and started a strike, withholding their rent checks until their grievances were dealt with. The conflict that arose from the tenants' dissatisfaction led to New York City's rent control laws.

Tudor City was designed as a series of apartment buildings that surround two blockfront-long shared parks. With its buildings arranged roughly in a U-shape open to the west – the tall Windsor, Tudor, and Prospect Towers along the eastern edge and the parks at its center – the complex turned its back on the noisome industrial area then located to the east and created a clearly identifiable neighborhood distinct from the grid around it.

The parks were not part of French's original scheme. In 1926 the company wrote, "after the buildings on 43rd Street and 41st Street and [Prospect and Tudor Towers] have been fully rented, these parks will be developed into possible forty-story hotels." But French soon changed his mind and by early 1927 made the parks a key part of the development's advertising campaign.

The parks originally encompassed approximately 64,000 square feet and followed the precedent of Gramercy Park in that only residents were to be issued keys for entry to them.

The North Park was designed by landscape architect Sheffield A. Arnold and laid out during the summer of 1927. A tree-moving machine was used to transplant full-grown trees to the site. The grass, shrubbery, flower beds, and Norway maples and spruce trees were tended by a uniformed and well-trained crew. The park had graveled walks, two timber structures – a pitched-roofed lychgate and a pergola – wooden benches, decorative iron lamp posts, and a central fountain, and was surrounded by a simple iron fence. In contrast, the South Park became a miniature golf course equipped with traps, a water hazard, nighttime illumination, and a professional golfer as an instructor. In 1930 a new course was opened across 41st Street, and the South Park was remade in the style of the North Park. Both parks have since been substantially narrowed and re-landscaped.

The Fred F. French Company advertised Tudor City heavily from its initial announcement until 1943. Included in the early campaign were two rooftop signs composed of incandescent light bulbs, one on either side of 42nd Street – on the north roof of Tudor Tower and the south roof of Prospect Tower – that could be seen from blocks away. The former was obscured by The Woodstock, and was removed c. 1933. The latter was retrofitted with neon in 1939; after falling in a storm in September 1949, it was replaced by a new version. This replacement, having lost its lighting tube years ago, is now a neglected rusting iron shell. In 1995, the co-op board of Prospect Tower requested permission from the Landmarks Preservation Commission to remove it, calling it ugly and dangerous, but the commission refused, on the ground of historical significance.

The sign and its supporting structure have been used many times as a setting for movies, TV, fashion magazines, and commercials