Many of the reforms were institutional in nature, that is, they were attempting to change and improve some fundamental rights and structures within America's government and society. These are traditionally, and by nature, very difficult to change.
So Dorothea Dix's attempt to reform the prison system into penitentiaries with the purpose of rehabilitating criminals was a major shift in policy. It would take decades to determine whether or not it was successful, but there has been some attempt at rehabilitation ever since.
Abolitionists of the time sought another fundamental change in the law and society, one that was met with determined and sometimes violent resistance. One could argue that actual abolition in 1865 would not have been possible without early activists "laying the groundwork" for that reform to become reality.
The answer to this varies widely because there were so many different kinds of reform movements going on during this time. Different movements had very different levels of success.
For example, a major movement was the movement for the abolition of slavery. You can argue about whether this movement succeded. On the one hand, slavery was abolished after the Civil War. On the other hand, most Northerners were not abolitionists and did not care that much about abolishing slavery. Slavery would not have been abolished as soon if the South had not tried to secede.
Movement for educational reform, like those of Horace Mann, were more successful. Mann's movement increased the amount of public schooling that was available, as well as the quality of teachers. On the other hand, movements for such things as women's rights did not take off very quickly. Women did not gain the right to vote for more than 70 years after the Seneca Falls Conference.
So the record of reform was very inconsistent and it is very difficult to say how much the reforms in general succeded.