We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness.

We’ve come a long way in the 236 years since our forefathers signed the Declaration of Independence. Over the last half-century, this once fledgling country has emerged as one of the richest, most powerful nations in the world.

Yet, despite our astounding progress, the story of the U.S. remains a tale of two countries – one a bounteous land of wealth and opportunity, the other a decimated hell of dead ends and abject poverty.

This past year my youngest daughter, Kimberly, a grad student, taught in two public elementary schools, both part of the Los Angeles Unified School District, in greater L.A.

School A sits in the tony outskirts of Beverly Hills, surrounded by manicured parks and artsy museums. The school is well-maintained, the fenced-in grounds open and welcoming. At recess, children laugh and shout as they chase each other through grassy fields, play ball on the basketball court, or climb on one of two play structures. Every Tuesday, parents roam freely around campus, visiting their children’s classrooms.

To enter school B, in the projects in East L.A., you must walk through a guarded chain-link fence, and then across the barren blacktop schoolyard. There are no fields – there is no grass – no courts or play structures here. The school’s graffiti-covered walls are tagged with gang symbols. There are no parents on this campus. After a recent near rape, except for teachers and staff, all adults have been banned.

But the stark physical difference barely hints at the story.

A community-funded booster club raises money for the arts and physical education at school A. Classrooms are equipped with computers, and every child receives his or her very own flash drive. Well-to-do parents send their chicly dressed kids to school with a nutritious lunch and wholesome snacks purchased at Whole Foods. Summers and over school breaks, the families vacation in exotic faraway places, like Israel or Asia.

These children thrive in advanced-level classes. Third-graders, sitting in pods, read and discuss interesting books and learn to write poetry. Most have already formulated plans for college and graduate school.

In school B, few kids live in two-parent homes. Many, their parents absent or jailed, live with grandparents or elder siblings; others reside in foster care. Children as young as six tout gang names and gap-toothed kids talk openly of incarceration and death. Children too young to have any real conception of sex have witnessed prostitution, sometimes at home, and first graders have been caught engaging in oral sex.

Children wear uniforms to spare embarrassment, because most cannot afford decent clothes. Families shop at the 99-cent store for whatever they need, including their groceries. Nearly 100 percent of the children are eligible for free or reduced lunch, and kids often come to school hungry, their last meal consumed at school the previous day.

There is no phys-ed or music or art class in school B. Teachers provide paper for homework assignments, as many kids have no access to paper at home. Here, kids struggle at grade-level or below. Not surprisingly, the drop-out rate is unconscionably high – many leave after sixth grade. For these children, who’ve done not a single thing in their young lives to merit a place in school B, college might as well be located on Mars.

Today, as we celebrate the birth of our nation, let us not forget how far we have come.

And let us remember how far we have yet to go.