But it was also the end of an era as American cities began to suburbanize and spread out.

但这也是一个时代的结束，美国城市开始郊区化并扩散开来。

The Sears Tower in Chicago got a little bit taller, but it was also the end of an era as American cities began to suburbanize and spread out.

芝加哥的西尔斯大厦增高了一点，但这也标志着一个时代的结束，因为美国城市开始郊区化和扩张。