Some clarification of what's been said. You can choose to which school you send your children, but if you are a property owner your taxes still go to the public school system. (When we say "public school" we mean government school, not a public school as England would have.) Besides the government schools we have two sorts of private (meaning non-government, but generally open to anyone with the money) schools, secular and religious. Religious schools are run by a particular religion and sect (e.g. Muslim Sunni, Christian Baptist, Christian Korean Methodist, Beth Torah) and get very little to no government funding. They generally spend less per pupil than do government schools; class sizes may be slightly smaller or slightly larger, but generally track similar. They may also be quite expensive, especially to those out of the religion. (Many people choose to send children to a religious school because of the quality education.) Secular private schools are almost without exception more expensive and generally provide a much better education. People also like the more expensive religious and secular private schools because they keep out the riff-raff - which generally means your children will be associating with other children who, because of their parents' resources, will tend to be in more influential positions later in life. Both religious and secular private schools also award some scholarships for sports, academic achievement, and the pursuit of diversity.
Within our government schools, we have several things that drive us away from quality education. In many (though not all) areas, teachers' unions actively fight qualifications and consequences for poor performance. Many school systems are stressed by older facilities; when your average building is forty or fifty years old, maintenance eats up a lot of your budget. We suffer from extreme political swings as well - progressives will achieve power and bring in math books with no math, which ushers in ultra-conservatives who bring in science books about how the Great Flood created the Grand Canyon 5,000 years ago, which ushers in progressives . . .
Probably our worst problems are societal. We simply no longer value hard work, or math or science. Our heroes tend to be celebrities and athletes, people whose talents contribute only marginally to society's prosperity. Our parents tend to want to be their children's friends, so that a parent whose child is disciplined at school is more likely to raise hell with the school board and the school than with the child. And we've developed a systematic bias for boosting children's self-esteem rather than giving them achievements deserving of high self esteem. But students who actually try - whose parents drive them to success and hard work - can still get a pretty good education in most school districts.