If you want to split a line feature into multiple line features, you can easily do so while maintaining all attribute data, history, links, and media in each of the new line features. Simply select the line feature you want to split, click on the menu button in the top-right of the feature details window, and click the Split Line option. Then select where along the line you would like to split it (you can split at multiple points at once) and click Save.

Watch the following video for a demonstration of how this is done.