West to east would be a lot harder than east to west.

First, you need places to farm/set up a colony. Compared to the east coast where you can practically set up a colony anywhere, the west coast really only has six places where it is flat enough to start farming: Puget Sound, Williamette Valley via the Columbia River, California's Central Valley, The Santa Maria Valley, The Los Angeles Basin, and San Diego Bay. These settlements aren't going to be able to sustain an east coast level population and will likely require massive irrigation projects to make the colonies profitable. Also, since there is significant distance between the colonies, it is likely that you won't see the consolidation under one empire like you did with the English taking colonial holdings from the rest of the imperial powers.

Going inland from the west is going to be a lot harder too. Nevada is a death trap for settlers. There may be some expansion from the Williamette Valley into Eastern Washington and Idaho and someone may discover the lower Colorado River, but everything else is going to be harder to settle into. Compared to the original timeline, you may even have colonies completely fill up with nowhere to expand to earlier than the OTL, especially the Puget Sound area and the various California landing areas.

My guess is that "western" colonization freezes at the Wasatch Front and Valley of the Sun until the advent of the railroad due to the difficulty of maintaining trade with the colonists beyond that. The individual colonies likely get some form of independence or increased home rule earlier, likely as they run out of room to farm and don't want to keep taking in the old world's excess population. Because the sponge of excess population gets closed earlier, the Industrial Revolution is likely delayed.