As we look specifically at the results for the quarter, we maintained top line momentum with organic sales of 12.7% with strong sales across categories and markets around the globe.
Our adjusted earnings per share were $0.77, more than double the prior-year, driven by strong organic sales growth, synergy realization, favorable currencies and lower interest expense.
Net sales growth to 5% to 7% adjusted earnings per share to a new range of $3.30 to $3.50 and adjusted EBITDA to a new range of $620 million to $640 million.
During the three months ending February, our brands grew faster than the category and we gained 2.1 share points globally as we benefited from the previously discussed distribution gains.
We anticipated these year-over-year declines, including a 13.9% decline in the U.S. during that four-week timeframe.
In the U.S., for example, the category was up 14.1% for that four-week period when you compare 2019 to 2021.
Looking at the U.S. AutoCare category, in the 13 weeks through February, we saw a healthy category growth of 7.4% as the category experienced both an increase in household penetration and existing consumer spending more on cleaning and maintaining their cars.
Finally, while we don't have e-commerce category data this quarter, our net sales have increased 70% across our combined portfolio, a reflection of our investments and ongoing focus which are paying off and positioning us to lead well into the future.
Specifically, we are on track to deliver over $120 million in synergies by the end of fiscal 2021, a portion of which is being reinvested in the business through innovation and brand building activities.
We have built an impressive innovation pipeline for our AutoCare business and have advanced our international growth plans with International AutoCare organic growth for the second quarter at 24%.
Our organic revenue growth of 12.7% combined with synergy realization, cost controls, lower interest expense and favorable currency headwinds resulted in strong adjusted earnings per share of $0.77, up more than double the prior-year second quarter and adjusted EBITDA of $148 million, up 20% compared to the prior year.
Both of our segments showed organic growth with the Americas up nearly 16% and International up 6%, and our Battery and Auto Care businesses grew benefiting from elevated demand and distribution gains that began last summer.
Adjusted gross margin decreased 110 basis points versus the prior year to 40.5% in line with our adjusted gross margin reported in the first quarter.
Additionally, our gross margin was negatively impacted by the lower margin profile associated with recent distribution gains and acquisitions, synergies of $14.2 million and favorable impacts from currency exchange rates partially offset these negative impacts.
A&P as a percent of sales was 4% relatively flat compared with the prior year's second quarter.
Consistent with our priorities, we invested on an absolute dollar basis in A&P to support our brands and innovation with total A&P spending of $4 million or 19% over the prior year.
Excluding acquisition and integration costs, SG&A as a percent of net sales was 16.7% versus 18.4% in the prior year, primarily the result of elevated sales experienced in the current year.
On an absolute dollar basis, adjusted SG&A increased $6 million in part because of the higher overheads associated with our top line sales growth and foreign exchange rate impacts.
We realized nearly $20 million in synergies this quarter, bringing the total for that first half of 2021 to $40 million.
Since our Battery and Auto Care acquisitions were completed, we have recognized approximately $109 million of synergies, exceeding our initial targets and we expect to realize an additional $10 million to $15 million over the balance of the year.
As I mentioned last quarter, we've taken advantage of favorable debt markets and refinanced a significant portion of our debt over the last 12 months.
We expect these refinancings to contribute to a $30 million reduction in our 2021 interest expense, of which $8 million was realized in the second quarter.
At the end of the quarter, our total debt was approximately $3.5 billion or 4.8 times net debt to credit defined EBITDA, with nearly 80% at fixed interest rates and an all-in cost of debt of 4.2%.
Net sales growth is now expected to be between 5% to 7%, owing in large part to a prolonged elevated battery demand in North America and favorable currency impacts.
Adjusted earnings per share is now expected to be in the range of $3.30 to $3.50.
Adjusted EBITDA is expected to be in the range of $620 million to $640 million.
And finally, adjusted free cash flow is expected to be at the low end of our previously provided range of $325 million to $350 million due to working capital requirements, mostly related to inventory as we look to rebuild safety stocks.
We will also benefit over the rest of the year as our gross margin in the third and fourth quarter of 2020 was burdened with one-time COVID-related costs of $9 million and $19 million, respectively.

Summary:
Our adjusted earnings per share were $0.77, more than double the prior-year, driven by strong organic sales growth, synergy realization, favorable currencies and lower interest expense.
Net sales growth to 5% to 7% adjusted earnings per share to a new range of $3.30 to $3.50 and adjusted EBITDA to a new range of $620 million to $640 million.
Our organic revenue growth of 12.7% combined with synergy realization, cost controls, lower interest expense and favorable currency headwinds resulted in strong adjusted earnings per share of $0.77, up more than double the prior-year second quarter and adjusted EBITDA of $148 million, up 20% compared to the prior year.
Net sales growth is now expected to be between 5% to 7%, owing in large part to a prolonged elevated battery demand in North America and favorable currency impacts.
Adjusted earnings per share is now expected to be in the range of $3.30 to $3.50.