in 1901是时间状语
the two 主语
opened 谓语动词
their first shoe store 宾语 （不细分了）
in downtown,Seattle 地点状语
This 主语
was 系动词
the start of what would become the retail legend of Nordstrom.Inc.表语
the start of sth..的开端
what would become the retail legend of Nordstrom 是介词 of 的 宾语从句
供参考,祝进步!