It was metricized with all the rest before that. What happened in 59 was harmonization with other countries including Canada, who had a different agreement on t

It was metricized with all the rest before that. What happened in 59 was harmonization with other countries including Canada, who had a different agreement on the metric yard. The older american definition was 1 yard = ​3600/3937 meter. The international metric yard is exactly 0.9144m. (A difference of 0.002mm)