When the arrival of a new MLS franchise in Seattle was announced in 2008 and it was clear that the USL Sounders were going to fold, the ECS decided to become supporters of the new club.

On the day of a home game the ECS congregates at bars in the Pioneer Square area, and marches together the half-mile distance from Occidental Park to Lumen Field.

[3] The European influence shows in songs that involve coordinated movement, such as pogoing and scarf waving, and in many traditional British football chants such as Sounders Till I Die and Guinness Boys.

Several sub-groups are designated by the Emerald City Supporters on geographical, cultural, or occupational lines.

To be considered an official regional sub-group there must be at least 25 ECS members affiliated with the group; groups based on a common cause other than geography (such as La Barra Fuerza Verde and Pride of the Sound) require 50 ECS members to be officially recognized.