Complex sentence: It was informally adopted following Canadian Confederation in 1867 and, from 1892, it was the official flag for use on Canadian merchant ships, but on land the official national flag was the Union Flag.
Split into simpler sentences: It was informally adopted following Canadian Confederation in 1867 and, from 1892, it was the official flag for use on Canadian merchant ships. On land, however, the official national flag was the Union Flag.