You have to be careful with those measurements. A U.S. pint is 16 oz., whereas an Imperial pint is 20. The ounces are somewhat different, too, but pretty close in size. However, cups, pints, and so forth differ noticeably. This makes it difficult to translate British recipes into American, and vice versa. And it’s one of the reasons that European recipes have standardised on metric weights of dry ingredients and mL for liquids, rather than on traditional volume measures for all.
The main thing is that 2 c = 1 pt, 2 pt = 1 qt., and 4 qts. = 1 gal, regardless of the system, but the quantities are definitely not the same, as is evidenced by the values in milliltires, centilitres, and litres.
The U.S. standard was the old English measures, and I well remember my Nana quoting the old saying, “A pint’s a pound, the world around.” The SI metrics are similarly calibrated, so that 1 L of water at standard temperature and pressure weighs 1 kg. (Bear in mind, however, that this may now vary slightly, because of re-standardisation based on physical constants, instead of standard weights and measures kept in London and Paris.)