There is no problem with removing it, just regrade the slope with the existing yard and reseed or sod.

Thanks. Was wondering why it was there in the first place.

Maybe just to keep people from walking on the grass

Totally can come out! You might need to rent a skid steer to help grade it.

I'd advise a comprehensive landscaping plan. A large plant nursery will be able to regrade / sod / install foundation plantings...and add a tree that, at maturity, won't be too large.

You blew it cutting that beautiful tree down.

People need to get over the mindset of a large tree in close proximity to a house is evil and forebodes all manner of doom! In many area of the country that are rather heavily treed naturally, trees planted or existing close to structures are commonplace. Tree roots are seldom an issue with foundation damage if the foundation is structurally sound - I'd be much more concerned about those of the water lovers and any underground plumbing. And it is almost impossible to replace the stately presence and shade generating capacity of a mature tree in one's lifetime if it is removed.

It is very simple to have a tree evaluated by a certified arborist to confirm it is healthy and structurally sound before deciding whether or not to remove. We should be leaving as many mature trees as possible in place rather than cutting them down willy nilly for no valid reason other than we are fearful of its location.

Save the materials from the retaining wall for a backyard garden/patio project.

Like large old trees but they can sometimes be a problem, especially if they're too close to the home. You could always plant another tree in the center of your front yard -- one more suitable for your intended purpose -- curb appeal and/or shade.

Some ideas

I like it much better without the tree. It blocked the entryway, it looked cramped in there, it overwhelmed the house and I would have wondered about foundation or sidewalk damage. I think its removal made the house look newer and more welcoming.

We have a yard that slopes slightly down toward the sidewalk and were thinking of _adding_ a little wall ;-)

In fact, we’re thinking to set the little retaining wall 2’ back from the sidewalk so we have a place to add plants.

From your photos it appears that the neighbors on both sides have less pitch in their yards than you do. While you can take the retaining wall out and re-grade the front yard you will be constrained by the grade of the neighbors and the existing pitch of your driveway. If you do that your new grade may seem a bit extreme. In the end it may cost more to have someone come out, cut the grade, dispose of the spoils and re-grade your front yard than it will to replace a small retaining wall like you currently have. @tc_kellygirl has an idea that could also work for you which is to push the wall back and do a small planting in front of it.

Thanks everyone for your ideas and responses. We hated to get rid of the tree but it was way too close for comfort. comfort. You would have had to see it in person. It blocked our view from the front door and provided a blind spot or hiding spot for potential theives. Also, the previous owner had issues where some roots messed up the walkway and it was redone. With the tree in the front and the one on the left side it was just too much. I like the idea of keeping the retaining wall and pushing it back some for planting. We will also be working on planting our flower beds soon.

Better photos to show how close the tree was too the house and how it blocked the door.

Also....ideas on what material we should replace the wall with. Use treated railroad ties again or stone...?

Use stone or concrete block. Railroad ties are considered hazardous waste (creosote content) and are rarely available for sale these days. And landscape timbers...or any other wood product, treated or not....will eventually rot due to contact with wet soil. And then you'll be back to the same replacement decision you are now.