The point is that the American units are now defined relative to metric units. As recently as the 1800s, the yard was defined as: "the Straight Line or Distan

The point is that the American units are now defined relative to metric units. As recently as the 1800s, the yard was defined as: "the Straight Line or Distance between the Centres of the Two Points in the Gold Studs of the Straight Brass Rod now in the Custody of the Clerk of the House of Commons whereon the Words and Figures "Standard Yard 1760" are engraved" ... That standard yard was destroyed in a fire in 1834, and a new standard yard was made using several copies of the original standard yard as reference. But now, it's just defined as an exact fraction of a meter. First as 36/39.370113 m, now as exactly 0.9144 meters.