帮我分析一下这个句子的结构

这是一道OG上的SC,大家帮我分析一下句子的结构，谢谢！

In one of the bloodiest battles of the Civil War, fought at Sharpburg, Maryland, on Sep 17, 1862, four times as many Amercians were killed as would later be killed on the beaches of Normandy during D-day.

= In one of the bloodiest battles of the civil war, the number of Americans died in that particular civil war = 4 x the number of Americans died on D-day.

"fought at ... 1862" defines the "one of the bloodiest battles of the Civil War".

在fought at Sharpburg, Maryland, on Sep 17, 1862,这样的一个最血腥的战场上死亡的人数是诺曼底登录当天死亡人数的4倍。

谢谢你们的回复！

In one of the bloodiest battles of the Civil War, fought at Sharpburg, Maryland, on Sep 17, 1862, four times as many Amercians were killed as would later be killed on the beaches of Normandy during D-day.

是否可以等同为：

Amercians were killed four times as many as would later be killed on .....