Brooks Brothers later found itself in an intellectual-property dispute with Ralph Lauren over the original polo button-down collar shirt, a garment central to the American preppy wardrobe. Brooks Brothers claimed rights connected to the design and sued Polo Ralph Lauren in an effort to protect its ownership of the shirt's branding or commercial identity. The dispute reflects a recurring tension in American fashion: a supposedly simple and widely imitated staple can carry enormous symbolic and commercial value once a heritage retailer presents itself as the garment's authentic originator.
The source does not provide the filing date, legal disposition, or the precise claims made in court, so the episode cannot responsibly be expanded into a claim that Ralph Lauren was definitively found to have plagiarized Brooks Brothers. What is clear from the account is that the two major American menswear names treated the button-down shirt not as generic wardrobe basics, but as contested intellectual property and brand heritage.

